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Item O11 0.11 J BOARD OF COUNTY COMMISSIONERS County of Monroe ire �f �rnl'PC ��l� Mayor Heather Carruthers,District 3 The Florida.Keys a Mayor Pro Tem Michelle Coldiron,District 2 V Craig Cates,District I David Rice,District 4 Sylvia J.Murphy,District 5 County Commission Meeting June 17, 2020 Agenda Item Number: 0.11 Agenda Item Summary #6973 BULK ITEM: No DEPARTMENT: County Attorney's Office TIME APPROXIMATE: STAFF CONTACT: Bob Shillinger(305) 292-3470 1:30 P.M. PUBLIC HEARING AGENDA ITEM WORDING: A public hearing to consider an emergency ordinance setting standards for when facial coverings must be worn in response to the COVID 19 pandemic. ITEM BACKGROUND: On March 1, 2020, Governor DeSantis issued Executive Order 20-52, which declared a state of emergency in Florida due to the COVID 19 virus and resulting pandemic. The Mayor first declared a state of local emergency on March 15, 2020 and has renewed that declaration every week since. Pursuant to the authority vested in her by Section 11-3 of the County Code, the Emergency Management Director issued a number of emergency directives including Directive 20-05 and later 20-08, which mandated the use of face coverings or masks in certain circumstances. Per F.S. 252.50, violations of emergency directives are enforceable as criminal offenses. This item was drafted and submitted by the June 2ad agenda deadline for the June 17th BOCC meeting. That deadline was two days before a June 4th Special meeting of the BOCC. The County Attorney intends to present the proposed ordinance at the June 4th special meeting. This public hearing has been advertised for the June 17th meeting in the event that the Board decides to: a) Consider any changes to the ordinance if the the BOCC decides to approve it on June 4th as an emergency ordinance; or b) Defer voting on the ordinance at June 4th until the June 17d'meeting. The proposed ordinance, as drafted, establishes both recommended standards and mandatory requirements. As drafted, the ordinance recommends that everyone who is away from their home carry a face covering and wear that covering when closer than six (6) feet to another person whom they don't live with. For those inside of a business establishment, the ordinance would require wearing of face coverings but proposes several exceptions, including: Restaurant patrons while dining and/or drinking while seated at a table Packet Pg. 2826 0.11 A gym patron engaged in a workout or class where at least 6 feet of distancing exists with the next closest patron. tD Barbershop or beauty salon customers when wearing a face covering would reasonably interfere with receiving services In areas of a business not open to the public, business owners, managers, and employees would not be required to wear face coverings, provided that 6 feet of distance exists between employees. This exception would not apply to the kitchen and food preparation areas of restaurants. Once the State allows bars to reopen, bar patrons would not be required to wear a face covering while consuming beverages and/or food. to Hotel and other lodging establishment guests would not be required to wear face coverings while inside of their units. (7) The ordinance contains language proposing an exemption for children but that specific age would need to be set by the board. While directives issued by the Emergency Management Director are enforceable under state law as misdemeanor offenses, adopting any requirements by ordinance would expand enforcement options to include code compliance citations, administrative hearings, and injunctions. The proposed ordinance would allow enforcement by any of these methods. PREVIOUS RELEVANT BOCC ACTION: 6/4/20 Special Meeting—Board considered ordinance. CONTRACT/AGREEMENT CHANGES: n/a STAFF RECOMMENDATION: Approval DOCUMENTATION: Mask Ordinance for June 17 2020 BOCC meeting Notice of Intention to Consider Adoption of County Ordinance (face coverings) BOCC 6 17 20 FINANCIAL IMPACT: Effective Date: Upon adoption Expiration Date: To be determined. Drafted as no later than June 1, 2021. Total Dollar Value of Contract: n/a Total Cost to County: Current Year Portion: Budgeted: Source of Funds: CPI: Indirect Costs: Estimated Ongoing Costs Not Included in above dollar amounts: Packet Pg. 2827 0.11 Revenue Producing: If yes, amount: Grant: County Match: Insurance Required: Additional Details: REVIEWED BY: Bob Shillinger Completed 05/29/2020 9:21 AM Bob Shillinger Completed 05/31/2020 9:29 PM Purchasing Skipped 05/29/2020 9:20 AM Budget and Finance Skipped 05/29/2020 9:20 AM Maria Slavik Skipped 05/29/2020 9:20 AM Kathy Peters Completed 06/01/2020 8:50 AM Board of County Commissioners Pending 06/17/2020 9:00 AM Packet Pg. 2828 ORDINANCE NO. -2020 AN UNCODIFIED ORDINANCE BY THE BOARD OF COUNTY COMMISSIONERS OF MONROE COUNTY, FLORIDA TO MANDATE THAT INDIVIDUALS WEAR A FACE COVERING IN PUBLIC IN CERTAIN CIRCUMSTANCES; ESTABLISHING A MINIMUM COUNTY-WIDE REQUIREMENT, EXCEPT TO THE EXTENT OF A MUNICIPAL ORDINANCE IN CONFLICT; PROVIDING FOR SEVERABILITY; PR VIDING FOR le ES REPEAL OF ALL ORDINANC , ��ONSISTENT HEREWITH; PROVIDING FOR T TTAL TO THE SECRETARY OF STATE AND ING FOR AN EFFECTIVE AND SUNSET DAT WHEREAS,the Board of County Co ' �oners of Monroe nty, Florida(hereinafter "Board") finds that COVID19 presents a dan 10 the health, safety, elfare of the public; and WHEREAS, the Centers fease Con � � advises that COVID-19 spreads T "i§ mainly from person to person through respiratory droplets produced when an infected person coughs, sneezes, or talks; these droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs; and studies and evidence on infection control report that these droplets usually travel around 6 feet(about two arms lengths); and WHEREAS, the CDC a� s that a �gnificant portion of individuals with coronavirus lack symptoms ("asymptomatic") and that even those who eventually develop symptoms ("pre ca - CD symptomatic") can transmit the virus to others before showing symptoms. This means that the N virus can spread between people interacting in close proximity—for example, speaking, coughing, or sneezing—even if those people are not exhibiting symptoms; and WHEREAS, the CDC recommends wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain in order to slow the spread of the virus 0 and help people who may have the virus and do not know it from transmitting it to others; and l WHEREAS,the CDC does not recommend wearing cloth face covering for children under the age of 2, or anyone who has trouble breathing, or is unconscious, incapacitated or otherwise unable to remove the mask without assistance; and WHEREAS, the CDC recommends only simple cloth face coverings for the general population and not surgical masks or N-95 respirators because these are critical supplies that must continue to be reserved for healthcare workers and other medical first responders; and WHEREAS, cloth face coverings are relatively inexpensive and readily available as the CDC states they can be made from household items and provides online guidance for making"do- it-yourself' coverings for people that cannot or do not want to buy one from the increasing sources producing and selling coverings; and Page 1 of 7 Packet Pg. 2829 WHEREAS, the Board finds it is in the best interest of public health, safety and welfare of the residents and workers of and visitors to the Florida Keys to require suitable face coverings in public locations to slow the spread of COVID19; and WHEREAS, the Board finds the inconvenience of an ordinance requiring the use of face coverings or other suitable face coverings is minimal compared to the risk to the health, safety, and welfare of the community were no such rule imposed; and WHEREAS, the Board finds implementation of this ordinance is necessary for the c preservation of the health, safety, and welfare of the communi 'z`�nd s E WHEREAS, Section 1(f) of Article VIII of the Constitution vests the Board with the authority to enact ordinances having countywide e , not inconsistent with state law, provided that such ordinance shall not be effecti� in a r 'cipality that has adopted an ordinance in conflict with the County ordinance, extent of su, nflict; andCL WHEREAS,the State of Florida has ri� ' tempted local govern Is from regulating in the field of minimum health requirements with re ` to C _ 19; and INN, ° WHEREAS, the County's ncy Mana t Director has issued interim rules requiring the use of face coverings pug r" �ti e autho in her by Section 11-3 of the County Code that are enforceable as m me s" law e '� ement through F.S. 252.47 and F.S. 252.50; and a, E WHEREAS�� tin ations' _ 'nce permit additional enforcement e� � P g � �. �, ca options through code' fiance injuncti ` - �' ief, and W im f ntin regulations for the Americans with Disabili '` at tli Aye r e e a public accommodation to permit an indivi o participar be ' from the b� ds services, facilities privileges advantages and acc Qdations of t blic modation when that individual poses a direct threat to the health ` afety of other d cu ors with disabilities who may be unable due to their 0 disability, to a face mas y acce the goods and services of the businesses through the provisions of cu , service or me delivery; and `Tq WHEREAS istrict Court of Appeal has defined the term business establishment for purpose liability to mean"a location where business is conducted, goods are made or stored or processed or where services are rendered." Publix Supermarkets, Inc. V. Santos, 118 So.3d 317 (Fla. 3d DCA 2013); and a� WHEREAS, the Florida Legislature has defined the term "transient public lodging establishment" to mean "any unit, group of units, swelling,building, or group of buildings within a single complex of buildings which is rented to guests more than three times in a calendar year for a period of less than 30 days or 1 calendar month, whichever is less, or which is advertised or held out to the public as a place regularly rented to guests." See, F.S. 509.013(4)(a)1. Page 2 of 7 Packet Pg. 2830 0.11.E NOW THEREFORE, BE IT ORDAINED BY THE BOARD OF COUNTY COMMISSIONERS OF MONROE COUNTY, FLORIDA: SECTION 1. Findings. The above recitals are adopted by the Board as legislative findings. SECTION 2. Definitions. For purposes of this ordinance, the following terms are defined as follows: 0 (1) Face Covering. A "face covering" is a material t11j1,povers the nose and mouth. It can be secured to the head with ties or straps or simply wrapped around the lower face. It can be made of a variety of materials, such as cotton, silk, or linen. A cloth face covering may be factory-made or sewn by hand, or can be improvised from household items. 2 (2) Business establishment. A "bu establishment" an indoor or semi- enclosed location where any buss` is conducted, goods made or stored or �-- processed or where services are ren ;� ,. The "busines blishment" also include locations where n-profit, go y e and quasi-go v dental entities o facilitate public interacts . , conduct bu (3) Lodging establishment. A gi blish e" all have the same meaning as the term "transi ublic lod esta ent" h F.S. 509.013(4)(a)1 (2019). a, A lodging t is a sp" ;c ty �� .ess e ,�� lishment. �; 4-11 SECTION 3. ecom =d s of con very perso r the of xxxx (yy) vho is away from his or her residence should ear a face co who r oser than 6 feet to another person with whom he or she not reside. 0 (2) Every on over t ge of xxx (yy) who is away from his or her residence should carry a ovenri able of immediate use. EEC (3) Each owner ager should establish rules for that business establishment that n encourage socia distancing and other protective measures for customers and 2 employees based upon guidelines provided by the Centers of Disease Control and the State Department of Health. E (4) Vulnerable Populations. Individuals older than 65 years of age and individuals with a serious underlying medical condition (such as chronic lung disease, moderate-to- severe asthma, serious heart conditions, immune-compromised status, cancer, diabetes, severe obesity, renal failure, liver disease) should continue to stay at home. When leaving home, these individuals should follow social distancing and other Page 3 of 7 Packet Pg. 2831 general mitigation guidance. Those living with vulnerable individuals should be aware of the exposure risk that they could carry the virus back home after returning to work or other environments where distancing is not practiced. Vulnerable populations should affirmatively inform their employer that they are a member of a vulnerable population so that their employer can plan accordingly. SECTION 4. Mandatory requirements. An owner, manager, employee, customer or patron of a business establishment must wear a face covering while in that business � establishment. r The requirements of this section do not a. Restaurant customers or pa while dirf sand/or consuming 2 beverages while seated at a, F b. A gym patron engaged in ' R. Workout or class wher east 6 feet of distancing exists with the nek est patr c. Barbershop or beauty salon cusp sons whe a face covering would �`..ably interfere _ ceiving services d. Business owners � and em es who are in an area of a business establishm " t � of open ustomers, patrons, or the public, provided that t o� e exist employees. This P � een em,�p�Y� - ��, ,,. p y u exce not app empl ho a resent in the kitchen or t ' o d Bever ti of a restaurant or food E es hment. e. Bar ns whiff onsumin verages and/or food, provided that the CO CD State h r ',@ z to re qp and provided that the Bar follows N rot0' } nlis the e for reopening. f. A` ��', es r ment gd en inside of the lodging unit including s but n ite �'� hotel ro m, motel room, vacation rental unit, ss timeshare`' .�t, or� l.� r unit. Any perso o is r xxx (yy) years of age, or is unconscious, incapacitated or otherwise unable to remove the mask without assistance. " fit, 'F The own tor, manager, and employee of a business or lodging establishme shall ensure that every individual in that establishment complies with this section. When a customer of a business establishment asserts that he or she has a disability that prevents the individual from wearing a mask, the owner, manager, or employee of the business establishment may exclude the < individual, even if they have a disability, as they pose a direct threat to the health and safety of employees and other customers, even if asymptomatic, and shall accommodate the disabled individual in a manner that does not fundamentally alter the operations of the business establishment nor Page 4 of 7 Packet Pg. 2832 jeopardize the health of that business's employees and other customers, such as providing curb service or delivery or other reasonable accommodation. SECTION 5. Penalties and Enforcement. This ordinance may be enforced in the following manner: (1) Criminal. c ,ti _Ie a. Any state, county, or municipal fforcement officer may arrest or issue a notice to appea ,f f y knowing and intentional violations committed in presence or through a procurement of an arrest � r fit. Vi ns maybe prosecuted by the State Attorney Erg �16th Judicia uit. b. A person found in on may be purrs up to 60 days in the County jail ail`.f��. a fine of up to $500. CL (2) Civil Citation o a. A code '_ f nce or la ` rcement officer m y upon observation''` lion by a who does not immediately i Y � put on a fac et fter recei ``��Y�� warning, issue a notice a pear or ci itatio ear I I , my Court. , .;" r. `E' i. Gi erson or` iness ! menosecuted under this E subse and t olat`' this ordinance may be unishe a fine o o $500.00. �� Adt« Y r � �; ��o'Witte of V � � ion A W f�` l �sco e compliance officer may, upon v� �_ f a viola � y a person who does not immediately n a " overing after receiving a warning, issue a notice o anon notice to appear before the code compliance boa specia agistrate of that officer's jurisdiction. b. Any ` on or business establishment found in violation of this ordin�� :o may be fined pursuant to part I of chapter 162,Florida t (4) Intun ive relief. a. The State Attorney of the 16th Judicial Circuit and/or the County Attorney may file an action for injunctive relief in Circuit Court seeking W to enjoin violations that occur throughout the County, except for violations that occur in a municipality that has adopted an ordinance in conflict with this ordinance. b. The City or Village Attorney for a municipality may file an action for injunctive relief in Circuit Court seeking to enjoin violations that occur with that municipality. Page 5 of 7 Packet Pg. 2833 (5) Private Right of Action. Any natural person may seek injunctive relief in the Circuit Court for the 16th Judicial Circuit to enforce violations of this section against a violator. Attorney's fees and costs incurred in an action to enforce this ordinance may be awarded to the substantially prevailing party at the discretion of the court. u (6) Defenses. An owner, manager, and/or employee of a business establishment shall not be liable in any enforcement action taken under this c section for the violations of a guest, cull er, and/or patron if that owner, manager, and/or employee directed t st, customer, and/or patron who E refuses to wear a face covering toy ` the premises or face prosecution of trespass. .i' a� SECTION 6. Severability. If any section, tion, sentenc �,� use or provision of this 3 ordinance is held by a court of competent juri n to be invalid the` finder of this ordinance CL shall not be affected by such invalidity. , SECTION 7. Applicability and,R, flict. This```«-� ' `� is intended to�� ve countywide application except within a munici ich has a d an ordinance in conflict this this ordinance pursuant to Article VIII, Se n e Florid ,F stitution. All County ordinances or parts of ordinances in conflict with or ' are he`d{ repealed to the extent of said conflict. SECTION 8. Effe Date. Ordinan' ' 11 take im ediate effect upon adoption and U shall be filed with the anent tate. CO �.� ors , '�_ � N SECTI ate. =ss res` l' ,< < or nded by subsequent act of the Board, this ordin "all sunse', ` ' lie 1 �l. SECTIO Codification ue to mporary nature of this ordinance the Board directs the Clerk to Seri ordinanc kthe ipal Code for publication on its website but with instructions to n dify the or ' Vince within the Monroe County Code. PASSED AN ,, ` O D by the Board of County Commissioners of Monroe County, Florida, at a regular meets, ' E yid Board held on the day of 2020. r � Mayor Heather Carruthers Mayor Pro Tem Michelle Coldiron Commissioner Craig Cates E Commissioner David Rice Commissioner Sylvia Murphy Page 6 of 7 Packet Pg. 2834 (SEAL) BOARD OF COUNTY COMMISSIONERS Attest: KEVIN MADOK, Clerk OF MONROE COUNTY, FLORIDA By: By: Deputy Clerk Mayor 0 le �01� E T 0 �y N r � Page 7 of 7 Packet Pg. 2835 0.11.b NOTICE OF INTENTION TO CONSIDER ADOPTION OF COUNTY ORDINANCE NOTICE IS HEREBY GIVEN TO WHOM IT MAY CONCERN that on June 17, 2020 at 1:30 P.M., or as soon thereafter as may be heard,in the Murray E. Nelson Government Center, 102050 Overseas Highway, Key Largo, Monroe County, Florida, the Board of County Commissioners of le Monroe County, Florida, intends to consider the adoption of the following County ordinance: M AN ORDINANCE BY THE BOARD OF COUNTY COMMISSIONERS OF MONROE COUNTY, FLORIDA MANDATING THAT INDIVIDUALS WEAR A FACE 2 COVERING IN PUBLIC IN CERTAIN CIRCUMSTANCES; ESTABLISHING A MINIMUM COUNTY-WIDE REQUIREMENT, EXCEPT TO THE EXTENT OF A cv MUNICIPAL ORDINANCE IN CONFLICT; PROVIDING FOR SEVERABILITY; PROVIDING FOR EFFECTIVE AND SUNSET DATES. Pursuant to Section 286.0105, Florida Statutes, notice is given that if a person decides to appeal any decision made by the Board with respect to any matter considered at such hearings or meetings, he will need a record of the proceedings, and that,for such purpose,he may need to ensure that a verbatim record of the proceedings is made, which record includes the testimony and evidence upon which the appeal is to be based. ADA ASSISTANCE: If you are a person with a disability who needs special accommodations in order to participate in this proceeding,please contact the County Administrator's Office, by phoning (305) 292-4441, between the hours of 8:30 a.m. -5:00 p.m., no later than five(5) calendar days prior to the scheduled meeting; if you are hearing or voice impaired, call "711': Live Closed Captioning is available via our web portal @ httg.IlmonroecounL l.igm2.com for meetings of the Monroe County Board of County Commissioners. c t� Dated at Key West, Florida, this 28th day of May, 2020. c KEVIN MADOK, Clerk of the Circuit Court 0 (SEAL) and ex officio Clerk of the Board of County Commissioners of Monroe County, Florida Publication dates: c KW Citizen (Wed) 6/3/20—Account# 143331 (BOCC) c Keys Weekly(Th) 6/4/20 -Account#2074 (BOCC) News Barometer (Fr) 6/5/20 -Account#NB007 (BOCC) 0 0 Packet Pg. 2836 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers I BMJ Open Journals Login Log out Basket v Search Q Latest Content Archive Authors About Browse by topic Home ,'' Archive ,'' Volume 5,Issue 4 E-1 Email alerts IRInfectious diseases Article Research k Text PDF A cluster randomised trial of cloth Article masks compared with medical info masks in healthcare workers 6 C Raina Maclntyrel,Holly Seale,Tham Chi Dung2,Nguyen Tran Hien2, Citation Tools Phan Thi Nga2,AbrarAhmad Chughtail,Bayzidur Rahman',Dominic E Dwyer3,Quanyi Wang4 Share Author affiliations+ Qa Abstract Responses P15 Article Editor's Note metrics Alerts The authors of this article,published in 2015,have written a response to their work in light of the COVID-19 pandemic.We PDF urge our readers to consider the response when reading the Help article. https://bmjopen.bmj.com/content/5/4/e006577.responses#covid- 19-shorta ges-of-ma sks-and-the-use-of-cloth-masks-a s-a-la st- resort Objective The aim of this study was to compare the efficacy of cloth masks to medical masks in hospital healthcare workers(HCWs).The null hypothesis is that there is no difference between medical masks and cloth masks. Setting 14 secondary-level/tertiary-level hospitals in Hanoi,Vietnam. Participants 1607 hospital HCWs aged>_18 years working full-time in selected high-risk wards. V Intervention Hospital wards were randomised to:medical masks,cloth masks ora control group(usual practice,which included mask wearing).Participants used the mask on every shift for 4 consecutive weeks. Main outcome measure Clinical respiratory illness(CRI),influenza-like illness(ILI)and laboratory-confirmed respiratory virus infection. Results The rates of all infection outcomeswere highest in the cloth mask arm,with the rate of ILI statistically significantly higher in the cloth mask arm(relative risk(RR)=13.00,95%CI 1.69 to 100.07) compared with the medical mask arm.Cloth masks also had significantly higher rates of ILI compared with the control arm.An analysis by mask use showed ILI(RR=6.64,95%CI 1.45 to 28.65)and laboratory-confirmed virus(RR=1.72,95%CI 1.01 to 2.94)were significantly higher in the cloth masks group compared with the Our privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 1/16 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers I BMJ Open Conclusions This study is the first RCT of cloth masks,and the results caution against the use of cloth masks.This is an important finding to inform occupational health and safety.Moisture retention,reuse of cloth masks and poor filtration may result in increased risk of infection. Further research is needed to inform the widespread use of cloth masks globally.However,as a precautionary measure,cloth masks should not be recommended for HCWs,particularly in high-risk situations,and guidelines need to be updated. Trial registration number Australian New Zealand Clinical Trials Registry:ACTR N 12610000887077. This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial(CC BY-NC 4.0) license,which permits others to distribute,remix,adapt,build upon this work non-commercially,and license their derivative works on different terms,provided the original work is properly cited and the use is non- commercial.See:http://creativecommons.org/licenses/by-nc/4.0/ View Full Text http://dx.dol.org/10.1 136/bmj open-2014-006 577 Statistics from Altmetric.com Picked up by 185 news outlets C124429 Blogged by 20 Referenced in 1 policy sources Tweeted by 20634 On 47 Facebook pages .� Mentioned in 2 Google+posts Reddited by 7 See more details On 3 videos 11 427 readers on Mendeley Request Permissions Strengths and limitations of this study • The use of cloth masks is widespread around the world, particularly in countries at high-risk for emerging infections,but there have been no efficacy studies to underpin their use. • This study is large,a prospective randomised clinical trial (RCT)and the first RCT ever conducted of cloth masks. • The use of cloth masks are not addressed in most guidelines for health care workers—this study provides data to update guidelines. • The control arm was'standard practice',which comprised mask use in a high proportion of participants.As such (without a no-mask control),the finding of a much higher rate of infection in the cloth mask arm could be interpreted as harm caused by cloth masks,efficacy of medical masks, or most likely a combination of both. Introduction The use of facemasks and respirators for the protection of healthcare workers(HCWs)has received renewed interest following the 2009 influenza pandemic,l and emerging infectious diseases such as avian influenza,2 Middle East respiratory syndrome coronavirus(MERS- coronavirus)3 4 and Ebola virus.5 Historically,various types of ..I..FL./....FF........,..I.../...F.......A•..L......,Ft...�..,..I..FL.....�.1-N L.--- Our privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 2/16 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers BMJ Open mid 19th century,followed later by respirators.?Compared with other parts of the world,the use of face masks is more prevalent in Asian countries,such as China and Vietnam.$—>> In high resource settings,disposable medical masks and respirators have long since replaced the use of cloth masks in hospitals.Yet cloth masks remain widely used globally,including in Asian countries,which have historically been affected by emerging infectious diseases,aswell as in West Africa,in the context of shortages of personal protective equipment(PPE).12,13 It has been shown that medical research disproportionately favours diseases of wealthy countries,and there is a lack of research on the health needs of poorer countries.1 4 Further, there is a lack of high-quality studies around the use of facemasks and respirators in the healthcare setting,with only four randomised clinical trials(RCTs)to date.1 5 Despite widespread use,cloth masks are rarely mentioned in policy documents,1 6 and have never been tested for efficacy in a RCT.Very few studies have been conducted around the clinical effectiveness of cloth masks,and most available studies are observational or in vitro.6 Emerging infectious diseases are not constrained within geographical borders,so it is important for global disease control that use of cloth masks be underpinned by evidence. The aim of this study was to determine the efficacy of cloth masks compared with medical masks in HCWs working in high-risk hospital wards,against the prevention of respiratory infections. Methods A cluster-randomised trial of medical and cloth mask use for HCWswas conducted in 14 hospitals in Hanoi,Vietnam.The trial started on the 3 March 2011,with rolling recruitment undertaken between 3 March 2011 and 10 March 2011.Participants were followed during the same calendar time for 4 weeks of facemasks use and then one additional week for appearance of symptoms.An invitation letter was sent to 32 hospitals in Hanoi,of which 16 agreed to participate.One hospital did not meet the eligibility criteria;therefore,74 wards in 15 hospitalswere randomised.Following the randomisation process,one hospital withdrew from the study because of a nosocomial outbreak of rubella. Participants provided written informed consent prior to initiation of the trial. Randomisation Seventy-four wards(emergency,infectious/respiratory disease, intensive care and paediatrics)were selected as high-risk settings for occupational exposure to respiratory infections.Cluster randomisation was used because the outcome of interest was respiratory infectious diseases,where prevention of one infection in an individual can prevent a chain of subsequent transmission in closed settings.8,9 Epi info V.6 was used to generate a randomisation allocation and 74 wards were randomly allocated to the interventions. From the eligible wards 1868 HCWswere approached to participate. After providing informed consent,1607 participants were randomised by ward to three arms:(1)medical masks at all times on their work shift; (2)cloth masks at all times on shift or(3)control arm(standard practice,which may or may not include mask use).Standard practice was used as control because the IRB deemed it unethical to ask participants to notwear a mask.We studied continuous mask use (defined as wearing masks all the time during a work shift,except while in the toilet or during tea or lunch breaks)because this reflects current practice in high-risk settings in Asia.$ The laboratory resultswere blinded and laboratory testing was conducted in a blinded fashion.As facemask use is visible intervention,clinical end points could not be blinded.Figure 1 outlines the recruitment and randomisation process. Our privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 3/16 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers BMJ Open Download figure Open in new tab Download powerpoint Figure 1 Consort diagram of recruitment and follow-up(HCWs,healthcare workers). Primary end points There were three primary end points for this study,used in our previous mask RCTs:8,9(1)Clinical respiratory illness(CRI),defined as two or more respiratory symptoms or one respiratory symptom and a systemic symptom;»(2)influenza-like illness(ILI),defined as fever >_38°C plus one respiratory symptom and(3)laboratory-confirmed viral respiratory infection.Laboratory confirmation was by nucleic acid detection using multiplex reverse transcriptase PCR(RT-PCR)for 17 respiratory viruses:respiratory syncytial virus(RSV)A and B,human metapneumovirus(hM PV),influenza A(H3N2),(H1 Nl)pdm09, influenza B,parainfluenza viruses 1-4,influenza C,rhinoviruses,severe acute respiratory syndrome(SARS)associated coronavirus(SARS-CoV), coronaviruses 229E,NL63,OC43 and HKU1,adenoviruses and human bocavirus(hBoV).1 8-23 Additional end points included compliance with mask use,defined as using the mask during the shift for 70%or more of work shift hours.9 HCWs were categorised as`compliant if the average use was equal or more than 70%of the working time.HCW were categorised as`non-compliant if the average mask use was less than 70%of the working time. Eligibility Nurses or doctors aged>_18 years working full-time were eligible. Exclusion criteria were:(1)Unable or refused to consent;(2)Beards, long moustaches or long facial hair stubble;(3)Current respiratory illness,rhinitis and/or allergy. Intervention Participants wore the mask on every shift for four consecutive weeks. Participants in the medical mask arm were supplied with two masks daily for each 8 h shift,while participants in the cloth mask arm were provided with five masks in total for the study duration,which they were asked to wash and rotate over the study period.They were asked to wash cloth masks with soap and water every day after finishing the shifts.Participants were supplied with written instructions on how to clean their cloth masks.Masks used in the study were locally manufactured medical(three layer,made of non-woven material)or cloth masks(two laver.made of cotton)commonlv used in Vietnamese Our privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 4/16 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers BMJ Open practices,which may or may not have included maskwearing.Mask wearingwas measured and documented forall participants,including the control arm. Data collection and follow-up Data on sociodemographic,clinical and other potential confounding factorswere collected at baseline.Participants were followed up daily for 4 weeks(active intervention period),and for an extra week of standard practice,in order to document incident infection after incubation.Participants received a thermometer(traditional glass and mercury)to measure their temperature daily and at symptom onset. Daily diary cards were provided to record number of hours worked and mask use,estimated number of patient contacts(with/without ILI)and number/type of aerosol-generating procedures(AGPs)conducted, such as suctioning of airways,sputum induction,endotracheal intubation and bronchoscopy.Participants in the cloth mask and control group(if they used cloth masks)were also asked to document the process used to clean their mask after use. We also monitored compliance with mask use by previously validated self-reporting mechanism.$Participants were contacted daily to identify incident cases of respiratory infection.If participants were symptomatic,swabs of both tonsils and the posterior pharyngeal wall were collected on the day of reporting. Sample collection and laboratory testing Trained collectors used double rayon-tipped,plastic-shafted swabs to scratch tonsillar areas as well as the posterior pharyngeal wall of symptomatic participants.Testing was conducted using RT-PCR applying published methods.19-23 Viral RNA was extracted from each respiratory specimen using the Viral RNA Mini kit(Qiagen,Germany), following the manufacturer's instructions.The RNA extraction step was controlled by amplification of RNA house-keeping gene(amplify pGEM)using real-time RT-PCR.Only extracted sampleswith the house keeping gene detected by real-time RT-PCR were submitted for multiplex RT-PCR for viruses. The reverse transcription and PCRswere performed in OneStep (Qiagen,Germany)to amplifyviral target genes,and then in five multiplex RT-PCR:RSVA/B,influenza A/H3N2,A(H1 N1)and B viruses, hMPV(reaction mix 1);parainfluenza viruses 1-4(reaction mix 2); rhinoviruses,influenza Cvirus,SARS-CoV(reaction mix 3); coronaviruses OC43,229E,NL63 and HKU1(reaction mix 4);and adenoviruses and hBoV(reaction mix 5),using method published by others.18 All sampleswith viruses detected by multiplex RT-PCRwere confirmed by virus-specific mono nested or heminested PCR.Positive controls were prepared by in vitro transcription to control amplification efficacy and monitor for false negatives,and included in all runs(except for NL63 and HKU1).Each run always included two negatives to monitor amplification quality.Specimen processing,RNA extraction, PCR amplification and PCR product analyses were conducted in different rooms to avoid cross-contamination.19,20 Filtration testing The filtration performance of the cloth and medical maskswas tested according to the respiratory standard AS/NZS1716.24 The equipment used was a TSI 8110 Filter tester.To test the filtration performance,the filter is challenged by a known concentration of sodium chloride particles of a specified size range and at a defined flow rate.The particle concentration is measured before and after adding the filter material and the relative filtration efficiency is calculated.We examined the performance of cloth masks compared with the performance levels—P1,P2(=N95)and P3,as used for assessment of all particulate filters for respiratory protection.The 3M 9320 N95 and 3M Vflex 9105 Our privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 5/16 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers I BMJ Open To obtain 80%power at two-sided 5%significance level for detecting a significant difference of attack rate between medical masks and cloth masks,and for a rate of infection of 13%for cloth mask wearers compared with 6%in medical mask wearers,wewould need eight clusters per arm and 530 participants in each arm,and intracluster correlation coefficient(ICC)0.027,obtained from our previous study.$ The design effect(deft)for this cluster randomisation trial was 1.65 (deft=1+(m-1)-ICC=1+(25-1)x0.027=1.65).As such,we aimed to recruit a sample size of 1600 participants from up to 15 hospitals. Analysis Descriptive statisticswere compared among intervention and control arms.Primary end pointswere analysed by intention to treat.We compared the event rates for the primary outcomes across study arms and calculated pvalues from cluster-adjusted X2tests25and ICC.25,26 We also estimated relative risk(RR)after adjusting for clustering using a log-binomial model under generalised estimating equation(GEE) framework.27 We checked forvariableswhich were unequally distributed across arms,and conducted an adjusted analysis accordingly.We fitted a multivariable log-binomial model,using GEE to account for clustering by ward,to estimate RR after adjusting for potential confounders.In the initial model,we included all the variables that had p value less than 0.25 in the univariable analysis,along with the main exposure variable(randomisation arm).A backward elimination method was used to remove the variables that did not have any confounding effect. As most participants in the control arm used a mask during the trial period,we carried out a post-hoc analysis comparing all participants who used only a medical mask(from the control arm and the medical mask arm)with all participants who used only a cloth mask(from the control arm and the cloth arm).For this analysis,controlswho used both types of mask(n=245)or used N95 respirators(n=3)or did not use any masks(n=2)were excluded.We fitted a multivariable log- binomial model,to estimate RR after adjusting for potential confounders.Aswe pooled data of participants from all three arms and analysed by mask type,not trial arm,we did not adjust for clustering here.All statistical analyseswere conducted using STATA VA 2.21 Owing to a very high level of mask use in the control arm,we were unable to determine whether the differences between the medical and cloth mask arms were due to a protective effect of medical masks or a detrimental effect of cloth masks.To assist in interpreting the data,we compared rates of infection in the medical mask arm with rates observed in medical mask arms from two previous RCTs,8,9 in which no efficacy of medical masks could be demonstrated when compared with control or N95 respirators,recognising that seasonal and geographic variation in virus activity affects the rates of exposure(and hence rates of infection outcomes)among HCWs.This analysis was possible because the trial designs were similar and the same outcomes were measured in all three trials.The analysiswas carried out to determine if the observed results were explained by a detrimental effect of cloth masks or a protective effect of medical masks. Results A total of 1607 HCWswere recruited into the study.The participation rate was 86%(1607/1868).The average number of participants per ward was 23 and the mean age was 36 years.On average,HCWs were in contact with 36 patients per day during the trial period(range 0-661 patients per day,median 20 patients per day).The distribution of demographic variables was generally similar between arms(table 1). Figure 2 shows the primary outcomes for each of the trial arms.The rates of CRI,ILI and laboratory-confirmed virus infections were lowest in TF.o moriir�l m�c4 arm fnlln,n,ori h.,0—---Trnl arm —A F.inF.ocT in Our privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 6/16 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers BMJ Open Table 1 VIEW INLINE VIEW POPUP Demographic and other characteristics by arm of randomisation Download figure Open in new tab Download powerpoint Figure 2 Outcomes in trial arms(CRI,clinical respiratory illness;ILI,influenza-like illness;Virus, laboratory-confirmed viruses). Table 2 shows the intention-to-treat analysis.The rate of CRI was highest in the cloth mask arm,followed by the control arm,and lowest in the medical mask arm.The same trend was seen for ILI and laboratory tests confirmed viral infections.In intention-to-treat analysis,ILI was significantly higher among HCWs in the cloth masks group(RR=13.25 and 95%CI 1.74 to 100.97),compared with the medical masks group.The rate of ILI was also significantly higher in the cloth masks arm(RR=3.49 and 95%CI 1.00 to 12.17),compared with the control arm.Other outcomeswere not statistically significant between the three arms. Table 2 VIEW INUNE VIEW POPUP Intention-to-treat analysis Among the 68 laboratory-confirmed cases,58(85%)were due to rhinoviruses.Other viruses detected were hMPV(7 cases),influenza B (1 case),hMPV/rhinovirusco-infection(1 case)and influenza B/rhinovirus co-infection(1 case)(table 3).No influenza A or RSV infections were detected. Table 3 VIEW INUNE VIEW POPUP Type ofvirus isolated Compliance was significantly higher in the cloth mask arm(RR=2.41, 95%CI 2.01 to 2.88)and medical masks arm(RR=2.40,95%CI 2.00 to 2.87),compared with the control arm.Figure 3 shows the percentage of participantswho were compliant in the three arms.A post-hoc analysis adjusted for compliance and other potential confounders Our privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 7/16 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers BMJ Open medical mask and control arms.Hand washing was significantly protective against laboratory-confirmed viral infection(RR=0.66,95% Cl 0.44 to 0.97). Table 4 VIEW INLINE VIEW POPUP Multivariable cluster-adjusted log-binomial model to calculate RR for study outcomes Download figure Open in new tab Download powerpoint Figure 3 Compliance with the mask wearing—mask wearing more than 7091.of working hours. In the control arm,170/458(37%)used medical masks,38/458(8%) used cloth masks,and 245/458(53%)used a combination of both medical and cloth masks during the study period.The remaining 1% either reported using a N95 respirator(n=3)or did not use any masks (n=2). Table 5 shows an additional analysis comparing all participants who used only a medical mask(from the control arm and the medical mask arm)with all participantswho used only a cloth mask(from the control arm and the cloth arm).In the univariate analysis,all outcomeswere significantly higher in the cloth mask group,compared with the medical masks group.After adjusting for other factors,ILI(RR=6.64, 95%CI 1.45 to 28.65)and laboratory-confirmed virus(RR=1.72,95%CI 1.01 to 2.94)remained significantly higher in the cloth masks group compared with the medical masks group. Table 5 VIEW INLINE VIEW POPUP Univariate and adjusted analysis comparing participants who used medical masks and cloth masks* Table 6 compares the outcomes in the medical mask arm with two previously published trials.$,9 This shows that while the rates of CRI were significantly higher in one of the previously published trials,the rates of laboratory-confirmed viruseswere not significantly different between the three trials for medical mask use. Tahip 6 VIEW INLINE VIEW POPUP Our privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 8/16 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers I BMJ Open On average,HCWsworked for 25 daysduringthe trial period and washed their cloth masks for 23/25(92%)days.The most common approach to washing cloth masks was self-washing(456/569,80%), followed by combined self-washing and hospital laundry(91/569, 16%),and only hospital laundry(22/569,4%).Adverse events associated with facemask use were reported in 40.4%(227/562)of HCWs in the medical mask arm and 42.6%(242/568)in the cloth mask arm(p value 0.450).General discomfort(35.1%,397/1130)and breathing problems(18.3%,207/1130)were the most frequently reported adverse events. Laboratory tests showed the penetration of particles through the cloth masks to be very high(97%)compared with medical masks(44%)(used in trial)and 3M 9320 N95(<0.01%),3M Vflex 9105 N95(0.1%). Discussion We have provided the first clinical efficacy data of cloth masks,which suggest HCWs should not use cloth masks as protection against respiratory infection.Cloth masks resulted in significantly higher rates of infection than medical masks,and also performed worse than the control arm.The controlswere HCWswho observed standard practice, which involved mask use in the majority,albeitwith lower compliance than in the intervention arms.The control HCWs also used medical masks more often than cloth masks.When we analysed all mask- wearers including controls,the higher risk of cloth maskswas seen for laboratory-confirmed respiratory viral infection. The trend for all outcomes showed the lowest rates of infection in the medical mask group and the highest rates in the cloth mask arm.The study design does not allow us to determine whether medical masks had efficacy orwhether cloth maskswere detrimental to HCWs by causing an increase in infection risk.Either possibility,or combination of both effects,could explain our results.It is also unknown whether the rates of infection observed in the cloth mask arm are the same or higher than in HCWs who do not wear a mask,as almost all participants in the control arm used a mask.The physical properties of a cloth mask,reuse,the frequency and effectiveness of cleaning,and increased moisture retention,may potentially increase the infection risk for HCWs.The virus may survive on the surface of the facemasks,29 and modelling studies have quantified the contamination levels of masks.30 Self-contamination through repeated use and improper doffing is possible.For example,a contaminated cloth mask may transfer pathogen from the mask to the bare hands of the wearer.We also showed that filtration was extremely poor(almost ON for the cloth masks.Observations during SARS suggested double-masking and other practices increased the risk of infection because of moisture, liquid diffusion and pathogen retention.31 These effects may be associated with cloth masks. We have previously shown that N95 respirators provide superior efficacy to medical masks,$ 9 but need to be worn continuously in high-risk settings to protect HCWs.9 Although efficacy for medical masks was not shown,efficacy of a magnitude that was too small to be detected is possible.$9 The magnitude of difference between cloth masks and medical masks in the current study,if explained by efficacy of medical masks alone,translates to an efficacy of 92%against ILI, which is possible,but not consistentwith the lack of efficacy in the two previous RCTs.8 9 Further,we found no significant difference in rates of virus isolation in medical mask users between the three trials, suggesting that the results of this study could be interpreted as partly being explained by a detrimental effect of cloth masks.This is further supported by the fact that the rate of virus isolation in the no-mask control group in the first Chinese RCTwas 3.1%,which was not cionifirantly rliffarant fn tha ratac of vin is icnlafinn in tha marliral mack Our privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 9/16 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers BMJ Open pathogens,which means the measured efficacy is against a different range of circulating respiratory pathogens.Influenza and RSV predominantly transmit through droplet and contact routes,while Rhinovirus transmits through multiple routes,including airborne and droplet routes.32,33 The data also show that the clinical case definition of ILI is non-specific,and captures a range of pathogens other than influenza.The study suggests medical masks may be protective,but the magnitude of difference raises the possibility that cloth masks cause an increase in infection risk in HCWs.Further,the filtration of the medical mask used in this trial was poor,making extremely high efficacy of medical masks unlikely,particularly given the predominant pathogen was rhinovirus,which spreads by the airborne route.Given the obligations to HCW occupational health and safety,it is important to consider the potential risk of using cloth masks. In many parts of the world,cloth masks and medical masks may be the only options available for HCWs.Cloth masks have been used in West Africa during the Ebola outbreak in 2014,due to shortages of PPE, (personal communication,M Jalloh).The use of cloth masks is recommended by some health organisations,with caveats.34-36 In light of our study,and the obligation to ensure occupational health and safety of HCWs,cloth masks should not be recommended for HCWs, particularly during AGPs and in high-risk settings such as emergency, infectious/respiratory disease and intensive care wards.Infection control guidelines need to acknowledge the widespread real-world practice of cloth masks and should comprehensively address their use. In addition,other important infection control measure such as hand hygiene should not be compromised.We confirmed the protective effects of hand hygiene against laboratory-confirmed viral infection in this study,but mask type was an independent predictor of clinical illness,even adjusted for hand hygiene. A limitation of this study is that we did not measure compliance with hand hygiene,and the results reflect self-reported compliance,which may be subject to recall or other types of bias.Another limitation of this study is the lack of a no-mask control group and the high use of masks in the controls,which makes interpretation of the results more difficult.In addition,the quality of paper and cloth masks varies widely around the world,so the results may not be generalisable to all settings.The lack of influenza and RSV(or asymptomatic infections) during the study is also a limitation,although the predominance of rhinovirus is informative about pathogens transmitted by the droplet and airborne routes in this setting.As in previous studies,exposure to infection outside the workplace could not be estimated,but we would assume it to be equally distributed between trial arms.The major strength of the randomised trial study design is in ensuring equal distribution of confounders and effect modifiers(such as exposure outside the workplace)between trial arms. Cloth masks are used in resource-poor settings because of the reduced cost of a reusable option.Various types of cloth masks(made of cotton,gauze and other fibres)have been tested in vitro in the past and show lower filtration capacity compared with disposable masks.7 The protection afforded by gauze masks increaseswith the fineness of the cloth and the number of layers,37 indicating potential to develop a more effective cloth mask,for example,with finerweave,more layers and a better fit. Cloth masks are generally retained long term and reused multiple times,with a variety of cleaning methods and widely different intervals ofcleaning.34 Further studies are required to determine if variations in frequency and type of cleaning affect the efficacy of cloth masks. Pandemics and emerging infections are more likely to arise in low- income or middle-income settings than in wealthy countries.In the Our privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 10/16 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers BMJ Open potential clinical efficacy of medical masks.Medical masks are used to provide protection against droplet spread,splash and spray of blood and body fluids.Medical masks or respirators are recommended by different organisations to prevent transmission of Ebola virus,yet shortages of PPE may result in HCWs being forced to use cloth masks.38-40 In the interest of providing safe,low-cost options in low income countries,there is scope for research into more effectively designed cloth masks,but until such research is carried out,cloth masks should not be recommended.We also recommend that infection control guidelines be updated about cloth mask use to protect the occupational health and safety of HCWs. Acknowledgments The authorswould like to thank the staff members from the National Institute of Hygiene and Epidemiology,Hanoi,Vietnam,who were involved with the trial.They thank aswell to the staff from the Hanoi hospitals who participated.They also acknowledge the support of 3M for testing of filtration of the facemasks.3M was industry partner in the ARC linkage project grant;however theywere not involved in study design,data collection or analysis.The 3M products were not used in this study. 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AAC contributed to the statistical analysis and drafting of the manuscript.BR was responsible for the statistical analysis and revision of the manuscript.DED contributed to the laboratory technical assistance and revision of the manuscript.QW assisted in comparing the rates of infection from two previous RCTs conducted in China and revision of the manuscript. Funding. Funding to conduct this study was received from the Australian Research Council(ARC)(grant number LP0990749). Competing interests: CRM has held an Australian Research Council Linkage Grant with 3 M as the industry partner,for investigator-driven research.3M has also contributed masks and respirators for investigator-driven clinical trials.CRM has received research grants and laboratory testing as in-kind support from Pfizer,GSK and Bio-CSL for investigator-driven research.HS had a NHMRC Australian-based Public Health Training Fellowship at the time of the study(1012631).She has also received funding from vaccine manufacturers GSK,bio-CSL and Sanofi Pasteur for investigator-driven research and presentations.AAC ...,.,a c,i.....,,....,....,..,.,.F........i...F,..�.,..nkn our _ privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 14/16 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers BMJ Open Ethicsapproval: National Institute for Hygiene and Epidemiology (NIHE)(approval number 051RB)and the Human Research Ethics Committee of the University of New South Wales(UNSW),Australia, (HRECapproval number 10306). 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For permission to use(where not already granted under a licence) please go to http://group.bmj.com/group/rights- licensing/permissions This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial(CC BY-NC 4.0) license,which permits others to distribute,remix,adapt,build upon this work non-commercially,and license their derivative works on different terms,provided the original work is properly cited and the use is non- commercial.See:http://creativecommons.org/licenses/by-nc/4.0/ ® Ir Consultant in Geriatric Medicine General with Geriatric Orthopaedic) West Dunbartonshire Salary:£82,699-£109,849 Working in Older People's Services,Vale of Leven Hospital with one other consultant,specialty doctor and frailty practitioner Recruiter:NHS Greater Glasgow and Clyde Apply for&his yob Consultant in Medicine for the Elderly(Movement Disorder( Greenock,Inverclyde £82,699 to£109,849(pro-rata if applicable) Based within a specialist Older People and Stroke Unit at the Inverclyde Royal Hospital(IRH)Greenock. 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Recruiter:Gloucestershire Hospitals NHS Foundation Trust Other content recommended for you Influenza syndromic surveillance and vaccine efficacy in the LJK Arrrled Forces,101/-..-2018 Mark Andrew Dermont et al.,J R Army Med Corps,2019 t Influenza syndromic surveillance and vaccine efficacy in the LJK Arrrled Forces,101/-..-2018 Mark Andrew Dermont et al.,BMJ Military Health,2019 i�J Our privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 15/16 6/15/2020 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers BMJ Open Antivirals for influenza-Like Illness?A randornised Controlled trial of Clinical and Cost effectiveness �G% in prirnary Cart (fV!...IC4 E):the ALIC4 E protocol Emily Bongard et al.,BMJ Open,2018 Irn"luerva-Associated Pediatric Deaths in the United States,1010--2016 Mei Shang et al.,Pediatrics,2018 Sponsored by Amgen Clinical Efficacy and Safety of Miniscalpel-Needle Treatment for Tension-Type Headache:A SVsternatic Review and Meta-AnalVsis Chan-Young Kwon et al.,Chinese Journal of Integrative Medicine,2020 CONTENT JOURNAL AUTHORS HELP Latest Content About Instructions for authors Contact us Archive Editorial board Submit an article Reprints Browse by topic Sign up for email alerts Editorial policies Permissions Most read articles Thank you to our reviewers Open Access at BMj Advertising Responses Top Cited Obstetrics and Gynaecology Instructions for reviewers Feedback form Articles BMj Author Hub Top Cited Infectious Diseases Articles Top Cited General/Family Practice Articles Top Cited Mental Health Articles 1 � f 018+ 601 BMJ Website Terms&Conditions Privacy&Cookies Contact BMj Cookie Settings Online:ISSN 2044-6055 Print:ISSN 2044-6055 Copyright©2020 BMj Publishing Group Ltd.All rights reserved. T,ICP`41 504 204 0-s-3 Our privacy and cookie policy Show Vendors https://bmjopen.bmj.com/content/5/4/e006577.long 16/16 Hello, My name is Dan Brooke. My educational background is health, nutrition, and medicine. I hold a Master's in Biomedical Science with coursework in immunology and epidemiology. I am a full-time resident of Key Largo and was born and raised here. I work alongside a primary care physician, RN, pharmacist, and nutritionist in my daily work, and Florida's response to Covid-19 has been at the forefront of my daily profession. I am writing you regarding Agenda #0.11,the proposed ordinance to require facial coverings in public areas at all time. While undoubtedly the intent of this proposal is to protect the health and well-being of the Monroe County public, I believe the ordinance proposed is disproportionate in its response, ineffective in its practicality and at most, dangerous, if followed in the strictest sense. In the following, I will detail a response to each of the contestable points that are noted as being cause for the proposed ordinance's execution.The responses will be free of any conjecture or opinion, and every claim presented will have an attached citation to either a scientific article from a peer-reviewed medical journal or an official statistic from the CDC/official epidemiological organization from the cited country. I am by no means dismissive of the SARS-COV-2 coronavirus, which causes COVID-19, but this ordinance in particular is counter-productive to the solution of safety and health for Monroe County. Afterwards, I will shortly detail the alternative actions that can be taken to better effect,without the requirement of judicial enforcement for non-compliance,which will save time and money, as well as improve public opinion of governmental performance while still remaining effective. Ordinance Claim:COVID-19 presents a significant danger to the health and safety to the public. While any disease presents a threat to the public, the Infection Fatality Rate (of those who have actually contracted the disease) is about 0.1%'and the median age of those deaths was 80 years old".This is comparable to a strong flu season at worst. Of those in the one of the most vulnerable age groups (70- 79) about 60% remain symptom free"'. About 80%of all tested positives remain symptom-free." Ordinance Claim:As COVID-19 is primarily transmitted through water droplets as a result of coughing, sneezing and talking AND that COVID-19 transmission can occur through pre-symptomatic individuals, all individuals should wear masks regardless of symptoms. The World Health Organization has made the statement that asymptomatic transmission of the virus is "rare" the initial CDC claim that pre-symptomatic/asymptomatic transmission occurs originates from a Singapore study in which out of 243 studied individuals, 7 had been as the result of presymptomatic/asymptomatic exposure."This statistics indicates about a 3%transmission rate for individuals with no shown symptoms. Ordinance Claim: Usage of non-surgical, non-N95 masks are effective for protecting against the transmission of COVID-19. There is no scientific evidence that cloth masks are effective in reducing the risk of SARS-COV-2 transmission. Surgical masks are the minimum requirement to show some effectiveness as source control, not as personal protection."" Of the currently available scientific data that evaluates facial covering effectiveness, no trial advocates for use of cloth masks as significantly effective, nor that even surgical masks are effective protection against transmission." Ordinance Claim:The usage of cloth-based facial coverings is necessary for the preservation of health, safety, and welfare of the community. The usage of cloth-based masks poses a potential danger to the health, safety and welfare of the community, not only for COVID-19 but for general viral exposure. When evaluating the effectiveness of facial masks against viruses, it was found that due to the moisture retention, reuse of cloth masks and poor filtration, that usage of cloth masks increased the rate of viral infection. 'x As cloth masks trap moisture and water droplets that can contain viruses, any contact or reuse of the mask results in an increased exposure to any viruses that are present. Having all of the submitted information, data, statistics, and scientific research, I implore the Board of County Commissioners to act in a progressive and informed regard, and not move forward with this ordinance for required facial-coverings. For the general public that would like to access a very straightforward analysis of COVID-19 as a whole, I recommend they access Swiss Policy Research, an international database on geopolitical information: https://swprs.org/a-swiss-doctor-on-covid-19/ In regard to the alternative: awareness, education and literature as a whole are more effective in the long-term for helping a population. Countries such as South Korea and Japan, which have had relatively low exposure rates for COVID-19 utilize masks in a different manner when compared to measures adopted by many other countries. It is a cultural norm to wear a mask when an individual is sick and source control is the most effective way to counter-act a transmissible disease and minimize its negative effects.A county-lead informational campaign for symptom awareness and correct mask utilization would do far more good than sweeping legislative measures that have financial and judicial repercussions. I hope that the information presented here helps our county make an informed decision for our future that truly benefits our community's safety and welfare as a whole. Sincerely, Dan Brooke. References: Systemic and mucosal antibody secretion specific to SARS-CoV-2 during mild versus severe COVID- 19 hops://www.biorxiv.org/content/10.1101/2020.05.21.108308v1.abstract "Provisional Death Counts for Coronavirus Disease (COVID-19) hops://www.cdc.gov/nchs/nvss/vsrr/covid weekly/index.htm "' Field Briefing: Diamond Princess COVID-19 Cases hops://www.niid.go.jp/niid/en/2019-ncov-e/9407-covid-dp-fe-O l.html '°Covid-19: four fifths of cases are asymptomatic, China figures indicate hltps://www.bmj.com/content/369/bmj.ml375 Transmission of COVID-19 by asymptomatic cases hgp://www.emro.who.int/health-topics/corona-virus/transmission-of-covid-l9-by-asymptomatic- cases.html 'Presymptomatic Transmission of SARS-CoV-2 Singapore, January 23—March 16, 2020 hltps://www.cdc.gov/mmwr/volumes/69/wr/mm6914el.htm °" Evaluating the efficacy of cloth facemasks in reducing particulate matter exposure hltps://www.nature.com/articles/jes20l642 "'Use of cloth masks in the practice of infection control —evidence and policy gaps hLyas://www.iiic.info/article/view/I 1366 "A cluster randomised trial of cloth masks compared with medical masks in healthcare workers hltps://bmjopen.bmj.com/content/5/4/eOO6577.long 6/15/2020 Use of cloth masks in the practice of infection control—evidence and policy gaps International Journal of Infection Control Search Ar&'vc� \,V 9 No 3 f2013) Onqma'Amiles Use of cloth masks in the practice of infection control — evidence and policy gaps ------------- Abrar Ahmad Chughtai pD� Scinool o�Pulblic Health andi C.ommun't,Medlidne .Fa 0r. Med"c'ne Ur .,of New Souik Wa'es Ausira"a Holly Seale P u,-A s 1led' School oc Pulblic Health amd C.ommun't,MedHdne Faculty op 2013-06-19 Med"c'ne Ur ".,,,ofNeNiSouii:Wa'es Ausiraiia Chandini Raina MacIntyre issu -Sclhoolo P W ubliclllea Pacuitvoc e Med"c'ne Unive_".,o:New Souik Wa'es Ausira"a 2,Naiionai 311 i h i.cation Re eatch and Su t jeillance o:Vaccine Ptcveniab'e Diseases(N,.-.1RS' -1he',.-.h Jk-JrCn.="os, Seciion We4,mead Austtai:a Original Articles DOI: Copyright conditions:Copyright on any research article in the International Journal of Abstract Infection Control(IJIC)is retained by the author(s).Authors grant DIC permission to Cloth masks are commonly used in low and middle income publish the article and identify itself as the countries.It is generally believed that the primary purpose of original publisher.Authors also grant any cloth masks is to prevent spread of infections from the wearer. third party the right to use the article freely However,historical evidence shows that they had been used in as long as its integrity is maintained and its the past for protection of health care workers(HCWs)from original authors,citation details and respiratory infections.Currently there is a lack of evidence on publisher are identified.DIC conforms to the the efficacy of cloth masks.In this paper,we examined the Creative Commons Attribution License evidence on the efficacy of cloth masks and discuss the use of (http://creativecommons.org)as terms and cloth masks as a mode of protection from infections in HCWs. conditions of publishing research articles.In We also discuss various methods to improve the effectiveness summary,anyone is free:-to copy, of cloth masks;for example;type of fabric,masks design and distribute,and display the work,-to make face fit.Further research is required to validate the use of cloth derivative works;-to make commercial use masks in HCWs for prevention of respiratory infections. of the work,as long as:-the original author must be given credit;-for any reuse or distribution,it must be made clear to others Author Biography what the license terms of this work are;-any of these conditions can be waived if the Abrar Ahmad Chughtai,School of Public Health and authors gives permission.Statutory fair use Community Medicine,Faculty of Medicine,University of and other rights are in no way affected by New South Wales,Australia the above.Authors'certification:In Research Officer,UNSW submitting a manuscript to DIC,authors are requested to certify that:-They are authorized by their co-authors to enter into these arrangements.-Theywarrant,on behalf of themselves and their co-authors, that:o the article is original,has not been formally published in any other peer- reviewed journal,is not under consideration by any otherjournal and does not infringe any existing copyright or any other third party rights;o they are the sole author(s)of the article and have full authority to enter into this agreement and in granting rights to DIC are not in breach of any other obligation. If the law requires that the article be published in the public domain,they will notify DIC at the time of submission;o the article contains nothing that is unlawful, libellous,or which would,if published, constitute a breach of contract or of confidence or of commitment given to secrecy,o they have taken due care to ensure the integrity of the article. https://www.ijic.info/article/view/l 1366 1/2 6/15/2020 Use of cloth masks in the practice of infection control—evidence and policy gaps I International Journal of Infection Control Information Pc,.Rea,ie,r Pot_.b,anan_ OPen out-nal Sys.e;,s Platform & workflow by OJS/ PKP https://www.ijic.info/article/view/l1366 2/2 6/15/2020 Evaluating the efficacy of cloth facemasks in reducing particulate matter exposure I Journal of Exposure Science& Environmental Epide... Published:17 August 2016 Evaluating the efficacy of cloth facemasks in reducing particulate matter exposure Kabindra M Shakya,Alyssa Noyes,Randa Kallin&Richard E PeltierE Journal of Exposure Science&Environmental Epiderniology 27,352-357(2017) 8888 Accesses V 13 Citations 1 610 Altmetric I Metrics Abstract Inexpensive cloth masks are widely used in developing countries to protect from particulate pollution albeit limited data on their efficacy exists.This study examined the efficiency of four types of masks(three types of cloth masks and one type of surgical mask)commonly worn in the developing world.Five monodispersed aerosol sphere size(30,100, and 500 nm,and 1 and 2.5 µm)and diluted whole diesel exhaust was used to assess facemask performance.Among the three cloth mask types,a cloth mask with an exhaust valve performed best with filtration efficiency of 80-90%for the measured polystyrene latex(PSL)particle sizes.Two styles of commercially available fabric masks were the least effective with a filtration efficiency of 39-65%for PSL particles,and they performed better as the particle size increased.When the cloth masks were tested against lab-generated whole diesel particles,the filtration efficiency for three particle sizes(30,100,and 500 nm)ranged from 15%to 57%.Standard N95 mask performance was used as a control to compare the results with cloth masks,and our results suggest that cloth masks are only marginally beneficial in protecting individuals from particles<2.5 µm.Compared with cloth masks, disposable surgical masks are more effective in reducing particulate exposure. Access through your institution Buy or subscribe Access options Rent or Buy Subscribe article to Journal Gel lime limii�d o�"al.ar.ic Se["al.jou�nal access acco,s or RcLdIu-,o. for 1/oa rrum $8.99 $270.00 -v,i-S.CJ_er sue -IL oror Buv ,1 NEI https://www.nature.com/articles/jes20l 642 1/6 6/15/2020 Evaluating the efficacy of cloth facemasks in reducing particulate matter exposure Journal of Exposure Science& Environmental Epide... All prices are NET prices. VAT wi II be added later in the checkout. Additional access options: Log in Access through your institution Learn about institutional subscriptions References I Davidson C,Phalen RE,Solomon PA.Airborne particulate matter and human health:a review.Aer Sci Technot 2005;39:737-749. 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I Maclmyre CR,Seale H,Dung TC,Hien NT,Nga PT,Chughtai AA et at.A cluster randomized trial of cloth masks compared with medical masks in healthcare workers.BMJ Open 2015;5:e006577. 2 Rengasamy S,Eimer B,Shaffer R.Simple respiratory protection —Evaluation of the filtration performance of cloth masks and common fabric materials against 20-1000 nm size particles.Ann Occup Hyg 2010;54:789-798. 10 https://www.nature.com/articles/jes20l 642 2/6 6/15/2020 Evaluating the efficacy of cloth facemasks in reducing particulate matter exposure Journal of Exposure Science& Environmental Epide... Wectronic Code of Federal Regulations(eCFR).Title 42:Public Health,Part 84—Approval of Respiratory Protective Devices. Available at:littp://-,vww.ecft,.gov/c,,gi-bin/text-idx? SID=a88cbO699d6516257aOaa2aaaf4Ob2b8&,-riode=42:1.0.1.7.67&t,gn= div5#42:1.0.1.7.67.6.19(28 August 2014). IM Lee SA,Grinshpun SA,Reponen T.Respiratory performance offered by N95 respirators and surgical masks:Human subject evaluation with NaCl aerosol representing bacterial and viral particle size range.An Occup Hyg 2008;52:177-185. 112 He X,Reponen T,McKay RT,Grinshpun SA.Effect of particle size on the performance of an N95 filtering facepiece respirator and a surgical mask at various breathing conditions.Aer Sci Technot 2013;47:1180-1187. IM He X,Reponen T,McKay R,Grinshpun SA.How does breathing frequency affect the performance of an N95 filtering facepiece respirator and a surgical mask against surrogates of viral particles. 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U Brauer,Amann M,Burnett RT,Cohen A,Dentener F,Ezzati M et at.Exposure assessment for estimation of the global burden of disease attributable to outdoor air pollution.Environ Sci Technot 2012;46:652-660. 2D van Donkelaar A,Martin RV,Brauer M,Kahn R,Levy R,Verduzco C et at.Global estimates of ambient fine particulate matter https://www.nature.com/articles/jes20l642 3/6 6/15/2020 Evaluating the efficacy of cloth facemasks in reducing particulate matter exposure Journal of Exposure Science& Environmental Epide... concentrations from satellite-based aerosol optical depth: Development and application.Environ Health Perspect 2010;118: 847-855. 21 Grinshpun SA,Haruta H,Eninger RM,Reponen T,McKay RT,Lee SA.Performance of an N95 filtering facepiece particulate respirator and a surgical mask during human breathing:Two pathways for particle penetration.J Occup Environ Hyg 2009;6: 593-603. 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Z3 Balazy A,Toivola M,Adhikari A,Sivasubramani SK,Reponen T, Grinshpun SA.Do N95 respirators provide 95%protection level against airborne viruses,and how adequate are surgical masks?Am J Infect Control 2006;34:51-57. 24 Balazy A,Toivola M,Reponen T,Podgorski A,Zimmer A, Grinshpun SA.Manikin-based performance evaluation of N95 filtering-facepiece respirators challenged with nanoparticles.Ann Occup Hyg 2006;50:259-269. 25 Eninger RM,Honda T,Adhikari A,Heinonen-Tanski H,Reponen T,Grinshpun SA.Filter performance of N99 and N95 face-piece respirators against viruses and ultrafine particles.Ann Occup Hyg 2008;52:385-396. 2fi Zhuang Z,Bradtmiller B.Head-and-face anthropometric survey of US respirator users.J Occup Environ Hyg 2005;2:567-576. 27 Yu Y,Benson S,Cheng W,Hsiao J,Liu Y,Zhuang Z et at.Digital 3-D headforms representative of Chinese workers.Ann Occup Hyg 2012;56:113-122. 29 Cho KJ,Reponen T,McKay R,Shukla R,Haruta H,Sekar P et at. Large particle penetration through N95 respirator filters and face- piece leaks with cyclic flow.Ann Occup Hyg 2010;54:68-77. 22 Huang S-H,Chen C-W,Chang C-P,Lai C-Y,Chen C-C. Penetration of 4.5 nm to 10 µm aerosol particles through fibrous filters.J Aerosol Sci 2007;38:719-727. Author information Affiliations 1.Department of Environmental Health Science,University of Massachusetts Amherst,Amherst,MA,USA Kabindra M Shakya,Alyssa Noyes,Randa Kallin&Richard E Peltier https://www.nature.com/articles/jes20l642 4/6 6/15/2020 Evaluating the efficacy of cloth facemasks in reducing particulate matter exposure Journal of Exposure Science& Environmental Epide... Corresponding author Correspondence to Richard E Peltier. Ethics declarations Competing interests The authors declare no conflict of interest. Additional information Author contributions REP,AN,and KMS contributed to the design,method,and data analysis. AN,RK,and KMS performed the experiments.All authors contributed to the article. Supplementary Information accompanies the paper on the Journal of Exposure Science and Environmental Epidemiology website Supplementary information Supplementary Information(DOC 294 kb) Rights and permissions Reprints and Permissions About this article Cite this article Shakya,K.,Noyes,A.,Kallin,R.et at.Evaluating the efficacy of cloth facemasks in reducing particulate matter exposure.J Expo Sci Environ Epidemiol 27,352-357(2017).https://doi.org/10.1038/jes.2016.42 Received12 November 2015Acceptedl3 June 2016 Publishedl7 August 2016Issue DateMay 2017 DOIhttps://cloi.ot,g/10.1038/jes.2016.42 Keywords inhalation exposure•particulate matter•personal exposure Subjects Environmental monitoring https://www.nature.com/articles/jes20l642 5/6 6/15/2020 Evaluating the efficacy of cloth facemasks in reducing particulate matter exposure Journal of Exposure Science& Environmental Epide... Further reading • Environmental determinants of cardiovascular disease;lessons learned frorn air pollution Sadeer G.AI-Kindi,Robert D.Brook[...] &Sanjay Rajagopalan Nature Reviews Cardiology(2020) • Analysis of roadside air pollutant concentrations and potential health risk of exposure in Hanoi,Vietnam Van Tai Tang,Nguyen Thi Kim Oanh[...] &Tran Ngoc Binh Journal of Environmental Science and Health,Part A(2020) • Aerosol Filtration Efficiency of Conanon Fabrics Used in Respiratory Cloth Masks Abhiteja Konda,Abhinav Prakash[...] &Supratik Guha ACS Nano(2020) • Facial protection for healthcare workers during pandemics;a sc€sping review Laura R Garcia Godoy,Amy E Jones[...] &Peter D Sullivan BMJ Global Health(2020) • Mascaras de teeido na contengio de goticulas respirat6rias-revisAo sistematiea Monica Taminato,Aline Mizusaki-Imoto[...] &Maria Stella Peccin Acta Pautista de Enfermagem(2020) Journal of Exposure Science&Environmental Epidemiology ISSN 1559-064X(online) ©2020 Springer Nature Limited https://www.nature.com/articles/jes20l642 6/6 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... See all See all 42 References 2 Figures ,I Dort ni ad citation Share .� ,nnr trur Avananre)°xpnl ZUZU wnn%Zbe neaps W 10.13140/RG.2.2.21662.08001 fine this publication &� De Kai 1_ Guy-Philippe Goldstein :014.44 The Hong Kong University of Science and Technology M1.15 Independent Researcher Alexey Morgunov +1 Vishal Nangalia i .d 7.82 University of Cambridge al 14.98 Royal Free London NHS Foundation Trust Show more authors eprints and early-stage research may not have been peer reviewed yet. tract We present two models for the COVID-19 pandemic predicting the impact of universal face mask wearing upon the spread of the SARS-CoV-2 virus—one employing a stochastic dynamic network based compartmental SEIR(susceptible-exposed-infectious-recovered)approach,and the other employing individual ABM(agent-based modelling)Monte Carlo simulation—indicating(1)significant impact under(near)universal masking when at least 80%of a population is wearing masks,versus minimal impact when only 50%or less of the population is wearing masks, and(2)significant impact when universal masking is adopted early,by Day 50 of a regional outbreak,versus minimal impact when universal masking is adopted late.These effects hold even at the lower filtering rates of homemade masks.To validate these theoretical models,we compare their predictions against a new empirical data set we have collected that includes whether regions have universal masking cultures or policies,their daily case growth rates,and their percentage reduction from peak daily case growth rates.Results show a near perfect correlation between early universal masking and successful suppression of daily case growth rates and/or reduction from peak daily case growth rates,as predicted by our theoretical simulations.Taken in tandem,our theoretical models and empirical results argue for urgent implementation of universal masking in regions that have not yet adopted it as policy or as a broad cultural norm.As governments plan how to exit societal lockdowns,universal masking is emerging as one of the key NPIs(non-pharmaceutical interventions)for containing or slowing the spread of the pandemic.Combined with other NPIs including social distancing and mass contact tracing,a"mouth-and-nose lockdown"is far more sustainable than a"full body lockdown",from economic,social,and mental health standpoints.To provide both policy makers and the public with a more concrete feel for how masks impact the dynamics of virus spread,we are making an interactive visualization of the ABM simulation available online at http://dek.ai/masks4all.We recommend immediate mask wearing recommendations,official guidelines for correct use,and awareness campaigns to shift masking mindsets away from pure self-protection,towards aspirational goals of responsibly protecting one's community. Discover the world's research 17+million members 135+million publications 700k+research projects res-uploaded by De Kai Author content tent may be subject to copyright. https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Models... 1/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... See all See all 42 References 2 Figures ,I Do ni ad citation Share .� Three successive randomised runs of the agent based model for 300 Interactive visualisation tool for the ABM simulation model to help days,with no mask wearing.Blue is susceptible,orange is exposed,re... policy makers and the general public gain a more concrete feel for ho... �rtisement :ontent uploaded by De Kai Author content other full-text sources- :ontent may be subject to copyright. Universal Masking is Urgent in the COVID-19 Pandemic: e SEIR and Agent Based Models, Empirical Validation, c Policy Recommendations N De Kai PHD MBA Guy-Philippe Goldstein MBA HKUST(University of Science&Technology),Hong Kong Ecole de Cuerre Economique,Paris,France International Computer Science Institute,Berkeley,CA,USA guyphilippeg@gmail.com [�] dekai@cs.ust.hk dekai@icsi.berkeley.edu @guypgoldstein [�] @dekail23 http://dek.ai ,---, Alexey Morgunov Vishal Nangalia PHD MBCHB FRCA University of Cambridge,UK University College London,UK Manifold Research,Cambridge,UK FLU At Ltd,London,UK asm63@cam.ac.uk alexey@manifoldresearch.com Royal Free Hospital,London,UK 0 @AlexeyMorgunov vishal.nangalia@gmail.com V9 @v alien CJ Anna Rotkirch PHD '-i Population Research Institute,The Family Federation of Finland anna.rotkirch@ vaestoliitto.fi @AnnaRotkirch https:/Iblogs.helsiki.fi/rotkirch 6 J 21 April 2020 r-+ MAbstract pirical data set we have collected that includes whether Ln regions have universal masking cultures or policies,their L!) We present two models for the COVID-19 pandemic daily case growth rates, and their percentage reduction M from peak daily case growth rates. Results show a near —i predicting the impact of universal face mask wearing upon the spread of the SARS-CoV-2 virusone employ- Perfect correlation between early universal masking and Cing a stochastic dynamic network based compartmen- successful suppression of daily case growth rates and/or Q tal SEIR (susceptible-exposed-infectious-recovered) ap- reduction from peak daily case growth rates,as predicted N proach,and the other employing individual ABM(agent- by our theoretical simulations. https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Models... 2/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... based modelling) Monte Carlo simulationindicating (1) cal Taken inara tandem our theoretical eort models and mpraal significant impact under(near)universal masking when at g gimplementation least 80%of a population is wearing masks,versus min- masking in regions that have not yet adopted it as policy or imal impact when only 50%or less of the population is *This collective work grew out of x Kinnernet discussion group wearing masks,and(2)significant impact when universal about COWD-I9 initiated by Goy-Philippe Goldstein.All authors con- masking is adopted early,by Day 50 of a regional out- tributed to the overall design and writing.Additionally,Goldstein for- See all See all> 42 Referetices 2 Figures ,I Dctt id ad ut ticii Share .� ratcS or rrouicuiauc ivasxs. io...varruarc...mcsc...uicorcucai pse and to the model design.and Rolkach and De Kai firs[drafted the models,we compare their predictions against a new em- report. 1 as a broad cultural norm.As governments plan how to exit introduce an SEIR (susceptible-exposed-infectious- societal lockdowns,universal masking is emerging as one recovered)model of the effects of mass face mask wear- of the key NPIs (non-pharmaceutical interventions) for ing overtime compared to effects of social distancing and containing or slowing the spread of the pandemic. Com- lockdown.In the second of two new theoretical models, bined with other NPIs including social distancing and we introduce a new interactive individual ABM(agent- mass contact tracing,a"mouth-and-nose lockdown"is far based modelling)Monte Carlo simulation showing how more sustainable than a"full body lockdown",from eco- masking significantly lowers rates of transmission. Both nomic,social,and mental health standpoints. To provide models predict significant reduction in the daily growth of both policy makers and the public with a more concrete infections on average under universal masking(80-90% feel for how masks impact the dynamics of virus spread, of the population)if instituted by day 50 of an outbreak, we are making an interactive visualization of the ABM but not if only 50%of the population wear masks or if simulation available online at http://dek.ai/masks4all.We institution of universal masking is delayed. recommend immediate mask wearing recommendations, We then compare the two new simulations presented official guidelines for correct use, and awareness cam- here against a new empirical data set we have collected paigns to shift masking mindsets away from pure self- that includes whether regions have universal masking cul- protection,towards aspiretiousl g s1s of responsibly pro- tures or policies,their daily case growth rates,and their tecting one's community percentage reduction from peak daily case growth rates. Since little precise quantitative data is available on cul- tures where masking is prevalent, we explain in some 1 Introduction depth the historical and sociological factors that support our classification of masking cultures. Results show a With almost all of the world's countries having imposed near perfect correlation between early universal mask- measures of social distancing and restrictions on move- ing and successful suppression of daily case growth rates ment in March 2020 to combat the COVID-19 pan- and/or reduction from peak daily case growth rates, as demic,governments now seek a sustainable pathway back predicted by our theoretical simulations. towards eased social restrictions and a functioning econ- To preview the key policy recommendations that our omy. Mass testing for infection and serological tests for two new SEIR and ABM predictive models and empirical immunity, combined with mass contact tracing,quaran- validation all lead to: tine of infected individuals,and social distancing,are rec- ommended by the WHO and have become widely ac- 1. Masking should be mandatory or strongly recom- knowledged means of controlling spread of the SARS- mended for the general public when in public trans- CoV-2 virus until a vaccine is available. port and public spaces,for the duration of the pan- Against this backdrop, a growing number of voices demic. suggest that universal face mask wearing,as practiced ef- fectively in most East Asian regions,is an additional,es- 2. Masking should be mandatory for individuals in es- sential component in the mitigation toolkit for a sustain- sential functions (health care workers, social and able exit from harsh lockdowns. The masks-for-all argu- family workers,the police and the military,the ser- ment claims that"test,trace,isolate"should be expanded vice sector,construction workers,etc.) and medical to"test,trace,isolate,mask". This paper presents cross- masks and gloves or equally safe protection should disciplinary,multi-perspective arguments for the urgency be provided to them by employers. Cloth masks of universal masking,via both new theoretical models and should be used if medical masks are unavailable. new empirical data analyses.Specifically,we aim to illus- trate how different degrees of mass face wearing affects 3. Countries should aim to eventually secure mass infection rates,and why the timing of introduction of uni- production and availability of appropriate medical versal masking is crucial. masks (without exploratory valves) for the entire In the first of two new theoretical models, we population during the pandemic. 2 https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Models... 3/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... See all See all 42 Refereuces 2 Figures ,I_ Do Td ad cit tics Share .� 4. Until supplies are sufficient,members of the general Leading political and medical experts who early were public should wear nonmedical fabric face masks advocated masking included Chinese CDC director- when going out in public and medical masks should general Prof. George Fu Gao (Servick, 2020), former be reserved for essential functions. FDA commissioner Scott Gottlieb and Prof. Caitlin Rivers of Johns Hopkins(Gottlieb and Rivers,2020),and 5. The authorities should issue masking guidelines to the American Enterprise Institute's roadmap(Gottlieb et residents and companies regarding the correct and al.,2020). optimal ways to make,wear and disinfect masks. In early April 202:, a iapidiy increasing number of governments from countries without a previous culture 6. The introduction of mandatory masking will benefit of mask wearing require or recorimend universal mask- from being rolled out together with campaigns,citi- ing including the Czech Republic,Austria and Slovakia. zen initiatives,the media,NGOs,and influencers in Additionally,public health bodies in the USA,Germany, order to avoid a public backlash in societies not cul- France(Acadmie nationale de mdecine,2020)and New turally accustomed to masking. Public awareness is Zealand have moved toward universal masking recom- needed that"masking protects your communitynot mendations(Morgunov et al.,2020),as shown below in just you". Figure 6. The vvorid Heaidi Organizaiion(2019)previously is- sued guidelines discouraging the use of masks in the pub- s Background lic. However in early April 2020 the World Health Or- F�ganization(2020)modified the guidelines,allowing self- Masks indisputably protect individuals against airborne made masks but rightly a1ressing the need to reserve med- transmission of respiratory diseases. A recent Cochrane ical masks for healthcare workers(Nebehay and Shalal, meta-analysis found that masking,handwashing,and us- 2020),and to combine masking-ith tha ether main NPI ing gowns and/or gloves can reduce the spread of respira- needed to combat the pandemic. The policy shifts of the tory viruses,although evidence for any individual one of WHO and other CDCs reflect advances in our scientific these measures is still of low certainty(Burch and Runt, understanding of this pandemic,and help legitimise the 2020). Currently,the lowest recorded daily growth rates altruistic"mask resistance"of civil society in this global in COVID-19 infections appear to be found in countries effort against COVID-19. with a culture of mass face mask wearing,most of whom ha,,e also made mask wearing in public mandatory during the epidemic,and most of whom are not currently locked 3 SEIR modelling of universal downan observation that we study systematically in sec- tion 5. masking impact Outside of East Asia,support for universal masking is emerging elsewhere across the globe.The Czech Repub- In the first of our two new theoretical models, we em- lic was the first non-Asian country to embrace and im- ployed stochastic dynamic network based compartmen- pose mandatory universal masking on March 11, 2020. tal SEIR modeling to forecast the relative impact of The Czech policy swiftly inspired various initiatives from masking compared to the two main other societal non- citizens, journalists and scientistse.g., De Kai (2020), pharmaceutical interventions,lockdown, and social dis- Howard and Fast.ai team(2020),Manioo(2020),Abaluck tancing. et al.(2020) Fene et al.(2020)-Finehern i 20201 Tufekci The SEIR simulations were fit to the current timeline in Ot»m d__P .P a gi„t—i_r_ ,._.,,t,,r_h ±E, ,.sks4all many Western countries,with a lockdown imposed March twoarafucld.gmask. Fho_i argu cats build on the the 24th (day 1) and planned to be lifted on May 31st. auiiity of the COVID-19 virus to spread from pre- and Universal masking is introduced in April.The simulation asymptomatic individuals who may not know that they continues for 500 days from day 0,or around 17 months. are infected,and to linger in airborne droplets. The experimental results strongly support the need for 3 https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Models... 4/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... universal masking as an alternative to continued lockdown See all See all, 42 Referetices 2 Figures ,I Do id ad cit ticii Share .� 111—d Y,_.—111 L r gb in 1APiwy 11) approaching Day 50. Pr(X;,=E I) =ahX,_E (2) In a SEIR model,the population is divided into com- Pr(X,,=I R) _16x,—z (3) partments which represent different states with respect to disease progression of an individual: susceptible Pr(X;,=I F)=µIhX,_I (4) (S), exposed (E), infectious (1) and recovered (R). where 6X2_A = 1 if the state of Xi, is A, or 0 if A susceptible individual may become exposed if they not,and where C(,(i) denotes the set of close contacts interact with an infectious individual at rate 3 (rate of of node i. transmission per S-I contact per time). From E,the individual progresses to being infectious (I) and even- tually recovered(R)with rates a (rate of progression) 3.1 Experimental model and -/ (rate of recovery), respectively. Additionally, We implemented SEIR dynamics on a stochastic dynamic individuals in I are removed from the population (i.e" network with a heterogeneous population. We assumed die of the disease)at rate µr (rate of mortality). an initial infected population of 1%and modelled the as- We used a SEIR model implemented' on a stochastic sumed effects of social distancing,lockdown,and univer- dynamical network that more closely mimics interactions sal masking over time on the rates of infection in the pop- between individuals in society, instead of assuming ulation. uniform mixing as is the case vh deterministic SEIR All SEIR models were built using the SEIRS+mod- models. Furthermore, such a roach allows setting elling tooh, version 0.0.14. The baseline model param- different model parameters for each individual, which eters are fit to the empirical characteristics of COVID-19 we use to model masking. In a network model,a graph spread,as documented in the SEIRS+distributed COVID- of society is built with nodes representing individuals lnotebooks.Specifically,we set 3=0.155, a=1/5.2 and edgestheir interactions. Each node has a state an / = 1/12.39. This parameterisation describes a S, E, I, R, or F(the latter added to represent dead SEIR model with best estimates for COVID-19 dynam- ics.individuals).Adjacent nodes form close contact networks of an individual,while contacts made with an individual The initial infected population (mitt) was set to 1%, from anywhere in the network represent global contacts and all others to 0%.The size of the total population was in the population. Varying the parameters affecting the set to 67,000(a representative typical case,that is a factor two levels of interaction, as well as setting network of 1,000 from the population of the UK). properties such as the mean number of adjacent nodes Social distancing. In the model, social distanc- ("close contacts")allows us to model the degree of social ing was defined as the degree distribution of the con- distancing and lockdown measures. tact network of an individual. Default interaction net- works were used,constructed as Barabasi-Albert graphs Formally, each node i is associated with a state Xi with in=9 and processes using the package function cus- which is updated based on the following probability tom exponential graph with different scale parameters. transition rates: Normal graph (scale=100) with mean degree 13.2, dis- tancing graph(scale=10)with mean degree 4.1 and lock- down graph(scale=5)with mean degree 2.2. Lockdown stringency. Lockdown stringency was modelled considering no stringent lockdown (i.e. only 'https:Hgithub.com/ryansmcgee/seirsplus '-https://github.com/ryansmcgee/seirsplus 4 https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Models... 5/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... See all See all 42 Refereuces 2 Figures ,I Do Td ad cit tics Share .� Figure 1:Simulation results for a representative scenario: universal masking at 80%adoption(red)flattens the curve significantly more than maintaining a strict lockdown(blue).Masking at only 50%adoption(orange)is not sufficient to prevent continued spread.Replacing the strict lockdown with social distancing on May 31 without masking results in unchecked spread. social distancing)or stringent lockdown using the local- Date fitting. The progression in the number of deaths ity parameter p, which was set to 0.02 during lockdown was used to fit the model to an approximate calendar date and 0.2 during social distancing phases.This dictates the representing Day 0.For the representative typical case of probability of individuals coming into contact with those the UK,this corresponded to Mar 23. outside of their immediate network.Assuming that indi- viduals have around 13 contacts in normal everyday life, social distancing will reduce this to 4 and lockdown to 3.2 Experimental results only 2. Figure 1 shows the simulation results for a representative Mask wearing. A gradual increase in mask wearing scenario:universal masking at 80%adoption(red)flattens was modelled using a linear increase in the proportion Effie curve significantly more than maintaining a strict lock- of individuals randomly allocated with a reduced rate of down(blue). Masking at only 50%adoption(orange)is transmission. The factor by which 3 was reduced was not sufficient to prevent continued spread.Replacing the conservatively set to 2.The period of time over which the strict lockdown with social distancing on May 31 without mask wearing went from 0 to maximum%was set to 10 masking results in unchecked spread. days.50%and 80%maximum values were considered. Our model suggests a substantial impact of universal 5 Figure 2:Simulation results for a representative scenario: universal masking at 80%adoption(red)results in 60,000 deaths,compared to maintaining a strict lockdown(blue)which results in 180,000 deaths. Masking at only a 50% https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Models... 6/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... dopton at (orange),is not s Y dent to revent co tmu d spread apd eventuate res lts m 4tl,OO( deaths.Replacing t o strict Irocekdown wttfi soda stanc n on May 1 withoupt masking results it�unc iecke sprea . masking. Without masking,but even with continued so- in 240,000 deaths. Replacing the strict lockdown with cial distancing in place once the lockdown is lifted,the social distancing on May 31 without masking results in infection rate will increase and almost half of the popu- unchecked spread. See all See all, 42 Refereuces 2 Figures ,I Do td ad cit tics Share .� H„..1-np p 1.11H L.-1—11. 1—v,.. 1IM—1 cF Agent Dasea moacning oL univer ued lockdown,illustrated in blue colour,does eventually result in brQing the disease under control after around sal masking impact 6 months. However,the economic and social costs of a "full body lockdown"will be enormous,which strongly In the second of our two new theoretical models, we supports finding an alternative solution. employed stochastic individual agent based modelling (ABM) as an alternative Monte Carlo simulation tech- In the model, social distancing and masking at both nique for understanding the impact of universal masking. 50%and 80%of the populationbut no lockdown beyond Agent based models have roots in various disciplines. A the end of Mayresult in substantial reduction of infec- stochastic agent program can be defined as a agent func- tion, with 80% masking eventually eliminating the dis- tion f : p —+ Pr(a) which maps possible percept vec- ease. Figure 2 shows the simulation results for a repre- tors to a probabilistic distribution over possible actions sentative nario: universal masking at 80% adoption (or to states that influence subsequent actions). In AI, (red)resuin 60,000 deaths,compared to maintaining Russell and Norvig(2009)summarise five classes of in- a strict lockdown(blue)which results in 180,000 deaths. tclligc nt agents:simple reflex agents,model-based reflex Masking at only a 50%adoption rate(orange)is not suf- agents,goai-based agents,utility-based agents,and learn- ficient to prevent continued spread and eventually results ing agents;note, however,that agents may also be sus- 6 ceptible to imperceptible environmental factors such as homes,only medical masks combined with other protec- viruses.Holland and Miller(1991)discuss artificial adap- tive equipment provide protection. Comparing different tive agents for modeling complex systems in economics. mask materials, medical masks have been found to be Bonabeau(2002)surveys agent based models for simulat- up to three times more effective in blocking transmission ing human systems. compared to homemade masks(Davies et al.,2013).Sur- As in other disciplines,ABM approaches in epidemiol- gical masks most efficaciously reduce the emission of in- ogy(-.cc,e.g.,Hunter et al. (2017). Tracy et al. (2018), fluenza virus particles into the environment in respiratory or Hwi is ri .l. (201S)) have several advantages com- droplets. Still, although masks vary greatly in their abil- pared to compartmental models which group undifferen- ity to protect, using any type of face mask(without an tiated individuals into large aggregates(like in the above exploratory valve) can help decrease viral transmission SEIR simulation). First, because the behavior and char- (Sande et al.,2008). acteristics of each agent is indelendent,they can simulate However,the effect of universal masking does not re- comDlex dynamic systems with less oversimplification of quire full protection from disease to be effective in low- rich variation among individuals.Second,because agents ering infection rates of COVID-19. Masks may be es- can be simulated in physical two- or three-dimensi—I parially orucial for containing the COVID-19 pandemic, spaces,they can better simulate the geometry of contact since.any infections appear to come from people with between individuals,which is highly relevant in epidemi- no signs of illness.For instance,around 48%of COVID- ology. Third, the randomization on each run makes the 19 transmissions were pre-symptomatic in Singapore and statistical variance more apparent than in the SIR fam- 62%in Tianjin,China(Ganyani et al.,2020). This sug- ily of models, whose smooth curves often misleadingly gests that masking needs to be universal and not restricted convey more certainty than warranted. Fourth, ABMs to individuals who think they may be infected. lend themselves well to visualization,as seen in Figure 5, Furthermore, the SARS-CoV-2 virus is known to which helps convey the non-linear behavior of complex spread througli a_rhn paitirl—(Leung et al.,2020)and dynamic systemsan especially relevant advantage when quite possibly via aerosolised droplets as well according the exponential effect of masking can be count"�i{ntuitive to Service(2020),van Doremalen et al.(2020),Santarpia in many cultures due to pre-existing cultural biases(Le- et al.(2020),and Liu et al.(2020).It n.ay linger in the air ung, 2020) and unconscious cognitive biases (De Kai, for and travel several meters,which is why social distanc- 2020). ing rules require at least 2 meters between individuals to be effective. T'Aask characteristics The ABM approach allows us to put masks on individual 4.2 Experimental model agents and to assign properties to those masks,to shed As a contrastive baseline we employed a compartmental light on the question of how face maskseven nonmedical SEIR model with the same parameters as given for our https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Models... 7/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... cloth maskscarry the promise to be so surprisingg.& effec- SEIR experiments of section 3. tive.The objective is to examine how even a smallYbarrier For the new agent based model, we implemented an to individual infection transmission can multiply into a environment con�i ting of a square wraparound two- substantial effect on the level of communities and popula- dimensional space,within which a population of individ- tions. ual agents reside in four states: susceptible(S),exposed Face masks work in two ways: They can protect an (E),infectious (1)and recovered(R). The wraparound See all> See all 42 Refereices 2 Figures f Do Td ad cit tics Share .� are worn to protect the wearer from being infected by an I%,and all others to 0%.The size of the total population ill person when in close and prolonged contact. In such was set to 200,but the wraparound feature of the two- classic situations, for instance in hospitals and elderly dimensional space in effect represents arbitrarily larger 7 Figure 3:Three successive randomised runs of the agent based model for 300 days,with no mask wearing.Blue is sus- ceptible,orange is exposed,red is infected,and green is recovered.The contrastive SEIR baseline model's predicted curves are shown in thinner,fainter lines. The ABM runs produce curves with a fine granularity of randomisation, centering on average around the ODE based SEIR curves. spaces that are approximated by replicated square tiles, break since empirically, the emergent SEIR curves sta- thus giving more accurate dynamics without boundary ef- bilise before the 300th day. fects from small spaces. To model the impact of masking,the following mask- To best fit the same empirical characteristics of ing parameters can be varied: COVID-19 spread as our SEIR models,we again set a= Mask wearing. Gradual increases (or decreases) in 1/5.2 and % = 1/12.39. Note that 3 is inapplicable in mask wearing can be modelled using parameterised rates the ABM since infection transmission between individu- of masking M(or unmasking U)in the proportion of un- als arises from physical proximity,which is more realistic masked(or masked)individuals. The parameters 7n_i, than randomly infecting other individuals anywhere with and Mn ,also allow modelling the minimum and maxi- some probability /3 with no regard to their physical lo- mum absolute numbers of masked agents.These masking cation. In the baseline Monte Carlo simulation, agents parameters can be dynamically adjusted any time during decide on a random destination location within a parame- any ABM run,to simulate varying policy decisions and terised radius of their current point,then proceed at a pa- cultural mindset shifts. rameterised speed to move there,and then repeat the pro- Mask characteristics.Varying degrees of mask effec- cess iteratively.We adjusted such ABM-specific parame- tiveness are modelled by the mask transmission rate T ters,as well as physical exposure distance,to optimise fit and mask absorption rate A,which denote the proportion to the baseline SEIR model curves,assuming none of the of viruses that are stopped by the mask during exhaling population to be wearing masks.Again,this was done so (transmission)versus inhaling(absorption),respectively. as to best approximate known COVID-19 dynamics. We set T=0.7 and A=0.7 to model the use of inexpen- ABM runs were for 300 days from the onset of the out- sive,widely available,and even nonmedical or homemade https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Models... 8/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... 8 See all See all 42 Refereuces 2 Figures ,I Do Td ad cit tics Share .� Figure 4:Four ABM runs under varying masking scenarios.(a)100%of the population wearing masks from the onset of the outbreak,with excellent suppression of infection spread.(b)0%of the population initially wearing masks,but instituting near universal masking of 90%of the population at day 50,still with significant suppression of infection spread. (c)0%of the population initially wearing masks,and instituting some masking of 50%of the population at day 50,with not much impact on infection spread. (d)0%of the population initially wearing masks,but instituting near universal masking of 90%of the population at day 75 with not much impact on infection spread. 9 https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Models... 9/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... See all See all 42 Refereices 2 Figures ,I Do Td ad cit tics Share .� FFP3 masks which in many regions need to be reserved within reach of most regions at the time of writing. for medical staff. In scenario (c), again the population is not initially wearing masks. On day 50, half the population dons 4.3 Experimental results masks,but unlike scenario(b)which succeeds with 90% universal masking, unfortunately 50% is an insufficient ABM simulation shows that universal masking can signif- level of mask adoption to suppress infection rates to a sig- icantly reduce virus spread if adopted sufficiently early, nificant degree. even if the masks are nonmedical or homemade. Figure 3 shows three successive runs for the baseline In scenario ,b the population again is not initially 7n=0 case with zero mask adoption.Each dot(which is wearing masks,but unlike scenario y the stew90% of da- in motion during simulation runs)represents an individ- sal masking is not instituted until day greatly instead of day ual agent,who may become exposed to the virus through de Waiting too long unfortunately greatly decreases the proxi y to other agents who are infectious. Blue dots degree to which infection rates can be suppressed. are he susceptible agents, orange dots are exposed To help policy makers and the general public gain a agents,red dots are infected agents, and green dots are more concrete feel for how masks impact the dynamics recovered agents. A dot with a white rectangle on it rep- of virus spread,we have made available online3 an inter- resents an agent who is wearing a mask. active visualisation tool for the ABM simulation model, The three baseline ABM runs show how chance plays as shown in Figure 5. The default view allows direct ad- a significant role in the dynamics of virus spread. Since j ustment in real time of the percent e of masked individ- ualeach simulation run is randomised,to decrease variance agents through a slider control Optional advanced requires observation over multiple runs. On average,the controls ow playing with various scenarios: whether baseline case with zero mask adoption adheres to the sim- masking i, sed,the adoption rate of masking,virus trans - pler SEIR model's predicted curves. mission and absorption rates through masks of varying Figure 4 compares typical runs for four scenarios quality,as well as other modelling parameters such as the that simulate how COVID-19 spreads among individual initial numbers of susceptible, exposed,infected, or re- agents under different masking scenarios, with the con- covered agents,and the contrastive baseline SEIR model trastive®aseline SEIR model curves shown in thin lines as parameters. a reference:(a)mo =100%meaning that the entire pop- ulation adopts mask at the onset of the outbreak on day 0;(b)mo = 0%7 in,,() =90%meaning that none of the population is wearing masks at the onset but that nearly 5 Evaluation of model predictions universal masking is instituted on day 50;and(c)mo = against empirical data on univer- 0%7m;() = 50%meaning that none of the population is wearing masks at the onset but that half of the population sal masking impact adopts masks on day 50,and(d)mo =0%7 7n7; =90% meaning that none of the population is wearing masks at For validation of the foregoing SEIR and ABM predic- the onset but that nearly universal masking is instituted on tive models it is necessary to compare against what little day 75. historical macro scale empirical data is available, since In scenario(a),a dramatic decrease in the number of precise numbers are not yet known for masking rates, infections is evident as a result of universal masking at the mask transmission and absorption rates, and infectious onset of the outbreak.Unfortunately,most regions outside but asymptomatic cases. East Asia missed the time window for scenario(a). In scenario(b),even though the population is not ini- tially wearing masks,if universal masking is instituted by 'http:Odek.ni/.asks4au 10 https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Mode... 10/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... See all See all 42Refereuces 2Figures ,I Do Td adcit tics Share .� Figure 5:Interactive visualisation tool for the ABM simulation model to help policy makers and the general public gain a more concrete feel for how masks impact the dynamics of virus spread,available online at http://dek.ai/masks4all. 5.1 Validation data Set order of the daily growth,Figure 5 presents these figures alongside features extraatcd data set denoting We collected a new data set describing the degree of suc- each country or region's(c)masking culture,(d)univer- cess in managing COVID-19 by countries or regions seg- sal masking policy,a4(c)lockdown policy.Additional mented by the prevalence or enforcement of universal clarification on definitions of a couple of these features masking. The data set covers(a)a selection of 38 coun- follow. tries or provinces in Asia,Europe and North America that have similar,high levels of economic development(based Masking culture a defined e an established prac- on World Bank GDP purchasing power parity per capita), we by a significant section of the general population to (b) detected COVID-19 cases from Jan 23 to April 10, wear face masks prior to the start ie the Covraturd-19 pan- 2020,and(c)characteristics of universal masking culture the ge r cursory review of the scientific literature and and/or universal masking orders or recommendations by the general press has identified Japan,Thailand,Vietnam (Burgess and Horii,2012), China's urban centers (Kuo, governments. 2014),Hong Kong(Cowling et al.,2020),Taiwan, Sin-and Snnth Korea(Yang(2014),1-nings(2020)) 5.2 Feature extraction as countries with „ h n,,i,trnt prartira,at least in the decade predating the Co.id-19 pandcnnic. Nevertheless, From our data set's 38 selected countries,we computed the notion of"culture" should not imply that the prac- (a)the daily growth of confirmed cases, as well as (b) tice of face mask wearing has been extensive and consis- reduction from peak of new cases. Sorted in increasing tent throughout time. For example,though this practice 11 may have fit with preexisting Taoist and health precepts of Chinese traditional medicine,its actual emergence may be relatively recent,starting with the industrialization of Japan at the start of the XXth century and both the flu pandemics of the XXth century as well as the rise of par- ticle pollution(Yang,2014). The rest of the above-listed east Asian countries has followed the same course in the second half of the XXth century, including China as it was confronting a severe particle pollution crisis in the first part of the 2010s(Kuo(2014),Li(2014),Hansstein and Echegaray (2018)). Beyond price, availability and government recommendation,the actual practice of mask- ing in the Asian general population may be mediated by factors such as social norms or neer-pressure,perception of o___competence,pact behaviors.or perception of the danger"' isstein and Eche ara 2018 As an exam- p le �..u.., g y, ). ple of the latter,in Hong Kong,masking was practiced by 79%of the general population during the 2003 SARS out- break,but by only a maximum of 10%of the general pop- https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Model... 11/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... matron aurm me mnuenza A pandemic inZUU`J(l:owl- ing�et al.,20 ). Universal masking policy.Additionally,to the extent that government recommendations or mandatory orders may shape perceptions and assist in masks:availability,it :nay amplify the masking practice in the general popula- tion_ it can thus he assumed that the maximum notene.v See all See all 42 References 2 Figures ,I Do ni ad ut ticn Share .� recommended order to the general population,issued at an early date,supported by the availability of face masks and amplified by a pre-existing"masking culture".In that case, we make the reasonable assumption that such na- tional situations may be used to validate our SFIR and ABM predictive models at maximum values(80-90%)for the percentage of the general population wearing masks. Figure 6: Epidemic daily growth and reduction from We also computed two additional meta-features to clas- peak daily growth, together with masking culture, uni- sify successful management of the epidemic outbreak. versal masking policy, and lockdown policy, from Jan- These meta-features help to highlight both(a)success in uary 23 to April 10,2020 for selected list of countries or suppressing growth from the start (e.g., Hong Kong or provinces with high GDP PPP per capita in Asia,Europe Taiwan)or(b)success in managing the epidemic by re- and North America.Universal masking was employed in ducing the number of new cases after a peak(e.g.,South every region that handled COVID-19 well.Sources:John Korea). Hopkins, Wikipedia,VOA News,Quartz,Straits Times, Successful suppression of daily growth is defined as South China Morning Post,ABCNews,Time.com,Chan- being below 12.5%daily growth(equivalent to number of nel New Asia, Moh.gov.sg, Reuters, Financial Times, cases doubling at the slower pace of 6 days or more)once Yna.co.kr,Nippon.com,Euronews,Spectatorsme.sk the number of detected cases first reached 30.These daily 12 Figure 7:Daily growth curves showing the impact of universal masking on epidemic control:epidemic trajectory after 30 detected cases in universal masking selected countries and provinces(green)vs.others(grey). Masking is nearly perfectly correlated with lower daily growth or strong reduction from peak growth of COVID-19. Sources: John Hopkins,Wikipedia,VOA News,Quartz,Straits Times,South China Morning Post,ABCNews,Time.com,Channel New Asia,Moh.gov.sg,Reuters,Financial Times,Yna.co.kr,Nippon.com,Euronews,Spectator.sme.sk growth rates are highlighted in green in Figure 6. breaks were countries or regions with either (1) estab- Successful reduction from peak is defined as a re- lished universal masking cultures or (2) mandatory or- cent, significant(>60%)reduction of new cases calcu- ders or government recommendations supported by sig- lated as the average of the last five day"efore April 10, nificant and early mask production destined for the gen- 2020 compared to the average of the three highest num- eral population. These countries or regions include Tai- https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Mode... 12/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... her of dail new cases up to April 10 2020 starting from wan,South Korea,Singapore,Japan,autonomous special the date when the number of detected cases first reached administrative regions such as Hong Kong or Macau,and 30.Again,these reductions from peak are highlighted in Chinese provinces such as Beijing,Shanghai,or Guang- green in Figure 6. dong. In effect,masking in public has been required in Taiwan, metropolitan areas in China such as Shanghai and Beijing (as well as Guangzhou, Shenzhen, Tianjin, See all See all 42 Refereices 2 Figures ,I_ Do td ad cit tics Share .� agent-based models as described in sections 3 and 4. Me 11 - wuaiuur uurvcisar uUaxuig)...M— In Figure 6,the green(successful , pre—ion of daily eaa ,how that most of the countries which have adopted growth a{�or reduction from peak)Zeaslow that as mass testing,tracking and quarantining,but lack a univer- of April I0, 2020, an overwhelming majority of coun- sal masking culture and clear recommendations and avail- tries or regions that have best managed COVID-19 out- ability for universal masking,have not achieved an equiv- 13 alent level of COVID-19 epidemic control as of April 10, sample),or the first group of countries and provinces with 2020. This nearly perfect correlation between early uni- masking culture and"early"universal masking orders.In versal masking and successful management of COVID-19 that first group,no countries or provinces had to endure outbreaks bears out our SFIR and ABM predictions. "strict lockdown". In Figure 7,daily growth curves were extracted from Validation of the need for early universal masking. our data set in order to reveal the impact of universal Yet even within this first group,the strength of early uni- masking on epidemic control on a time axis.Results show versal masking recommendations from the government that universal masking is nearly perfectly correlated with may impact the proportion of the general population actu- lower daily growth rates of COVID-19 cases over time, ally wearing masks and thus the level of epidemic control, again valuing the predictions from our SFIR and agent as per our models'SFIR and ABM predictions.For exam- based models. ple,Singapore initially encouraged people to wear masks In Figure 8, daily growth was plotted against versus only when feeling unwell.Then,on April,5,the govern- percentage reduction from peak daily daily growth.Green ment changed policy and decided to distribute reusable points,representing countries or regions with early uni- face masks to all households (Cheong, 2020). On the versal masking, disproportionately fall within the two other end, Hong Kong decided by January 24, 2020 to lower quants which represent successful management advise the general population to wear surgical masks in of COVI 19 outbreaks. Red points,representing coun- crowded places and public transports(Hong Kong Depart- tries with strict lockdowns but not universal masking, ment of Health,2020).As car,be ebserved from Figure 6, nearly all fall in the two upper quadrants which repre- as of April 10,2020,the characteristics for epidemic con- sent less successful management of COVID-19 outbreaks. trol in terms of daily growth and peak from reduction are Light green points,representing countries or regions with better for Hong Kong th�xr for Singapore. These varia- late universal masking,tend to fall in the middle regions. tions may be related to levels of adhere@e to masking Again,the strong correlation of universal masking with by the general population. Though there are no available successful control of COVID-19 case growth bears out data as of April 10, 2020 as per adherence to universal our SFIR and agent based models'predictions. masking in Singapore,telephone surveys in Hong Kong Validation of the need for universal masking. These done in February 11-14,2020 and then in March 10-13, validations highlight the gradual nature of the protection 2020,both after Department of Health public advice,have against COVID-19 achieved with a higher fraction of the shown declared masking adherence at the very high levels population practicing masking,as observed in the SFIR of 97.5%and 98.8%respectively when going out(Cowl- and ABM simulations when comparing situations with ing et al.,2020).Assuming the adherence level to mask- 80-90%universal masking versus only 50%masking or ing was lower in Singapore since the general population none. In countries or provinces with masking culture order came much later,this would support our SFIR and and universal masking orders or recommendations be- AB_A4 predictions of the need for early institution of uni- fore March 15,2020,the average daily growth was 5.9% versal masking. and the reduction from peak was 74.6%. In the coun- Although these correlations may also be sensitive to tries without masking culture and universal masking or- other unobserved factors,the theoretical SFIR and ABM ders or recommendations after March 15,2020,the aver- predictions as empirically validated in the various ways age daily growth was 14.2%and the reduction from peak described here call for urgent policy and public action was 45.8%.Finally,for the rest of the other countries,the even as further enquiry is pursued into the effects of mask- average daily growth was 17.2%and the reduction from ing. Our results also confirm and amplify other previ- peak was 37.4%, the lowest results of the sample. The ous findings.A recent macro-level regression analysis by latter group includes countries that have gone into"strict economists at Yale University,taking into account mask- lockdown" (or mass home quarantine)for 20 out of 27 ing cultures and times of country COVID-19 policy re- countries(74%). This is much higher than for the inter- sponses,estimated that growth of COVID-19 rates only mediate group of countries without masking culture and half that of mask wearing countriesthe growth rate of "late"universal masking orders (2 out 4,or 50%of the confirmed cases is 18%in countries with no pre-existing https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Mode... 13/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... 14 See all See all 42 Refereuces 2 Figures ,I Do Td ad cit tics Share .� Figure 8: Visual representation of epidemic daily growth versus percentage reduction from peak daily daily growth in quadrants showing the impact of universal masking on epidemic control:and reduction from peak,from January 23 to April 10,2020 for selected list of countries or provinces with high GDP PPP per capita in Asia,Europe and North America.Masking is nearly perfectly correlated with lower daily growth or strong reduction from peak growth of COVID-19. Sources: John Hopkins,Wikipedia,VOA News,Quartz,Straits Times,South China Morning Post, ABCNews,Time.com,Channel New Asia,Moh.gov.sg,Reuters,Financial Times,Yna.co.kr,Nippon.com,Euronews, Spectator.sme.sk mask norms and 10%in countries with such norms,while 6 Conclusion: Universal masking the growth rate of deaths is 21%in countries with no mask needs broad support and clear norms and I I%in countries with such norms.The authors note that such a 10%reduction in transmission probabili- guidelines ties could correspond to a per capita gain of$3,000-6,000 per each additional cloth mask, and that the economic Our SEIR and ABM models suggests a substantial im- benefits of each medical mask for healthcare personnel pact of timely universal masking. Without masking,but could be substantially larger(Abaluck et al.,2020). even with continued social distancing in place once the lockdown is lifted,the infection rate will increase and al- most half of the population will become affected. This scenario would potentially lead to over a million deaths in a population the size of the UK.Social distancing and 15 https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Mode... 14/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... See all See all 42 References 2 Figures ,I Do ni ad citation Share .� itations(0) References(42) Case for Universal Cloth Mask Adoption and Policies to Increase Supply of Medical Masks for Health Workers icle 2020 ason Abaluck Judith A.Chevalier Nicholas A Christakis Sten H.Vermund may be able to spread coronavirus just by breathing,new report finds icle 2020 SCIENCE °rt Service sol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1 icle 'a r„ 'a;;z https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Mode... 15/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... 2020 NEW ENGL J MED leeltje van Doremalen Trenton Bushmaker Dylan H.Morris Vincent Munster physical interventions help reduce the spread of respiratory viruses? See all See all 42 References 2 Figures ,I Dote ni ad citation Share .� Burch Christopher Bunt pen-data-driven agent-based model to simulate infectious disease outbreaks icle 0r„ 0' 2018 PLOS ONE lizabeth Hunter Brian Mac Namee John D.Kelleher Show abstract oring motivations behind pollution-mask use in a sample of young adults in urban China icle 0r„ 0' 2018 rancesca Hansstem Fabian Echegaray Show abstract eling the Effectiveness of Respiratory Protective Devices in Reducing Influenza Outbreak:Modeling the Effectiveness of Respiratory Protective Devices icle 0", 0' 2018 RISK ANAL ing Yan Suvajyoti Guha Prasanna Hariharan Matthew Myers Show abstract it-Based Modeling in Public Health:Current Applications and Future Directions icle -*> 'a r„ 'a;(z 2018 ANNU REV PUBL HEALTH Aelissa Tracy Magdalena Cerda Katherine M Keyes Show abstract icial Intelligence---A Modern Approach )k 1995 in J Russell Peter Norvig xonomy for Agent-Based Models in Human Infectious Disease Epidemiology icle 0r„ 0' 2017 JASSS J ARTIF SOC S lizabeth Hunter Brian Mac Namee John D.Kelleher Show abstract Show more Recommendations https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Mode... 16/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... Project Cyber-defense Guy-Philippe Goldstein See all See all 42 References 2 Figures ,I Dote ni ad citation Share .� Project "Childlessness in Europe.Contexts,Causes,and Consequences"(2017),ed.by Michaela Kreyenfeld and Dirk Konietzka:Springer Dirk Kometzka Michaela Kreyenfeld Ann Berrington [...] Martin Kohli The book provides an overview of the recent trend towards a"life without children"across Europe.It seeks answers to questions like:What are the determinants of childlessness in the 21st century...[m=cre] Project Recent human evolution Alexandre Courtiol Virpi Lummaa Michel Raymond [...] Stephen C Stearns I am interested in recent human evolution.I want to understand how the major environmental changes we triggered impact on the way we evolve. Project Consequences of forced migration John Loehr Robert Lynch Johanna Mappes [...] Kevin Middleton https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Mode... 17/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... Preprint x`,a Face Masks Against COVID-19:An Evidence Review Ap ri 1 2020 Jeremy Howard Austin Huanq Zhiyuan Li [...] Anne W.Rimoin See all, See all, 42 References 2 Figures ,I Doom ad citation Share .� multiple areas.1)transmission characteristics of COVID 19,2)filtering characteristics and efficacy of masks,3)...[Show full abstract] vl v:Pull-t�'Xt Preprint ..- >..010 ,a. r i To mask or not to mask:Modeling the potential for face mask use by the general public to curtail th... Ap ri 1 2020 Steffen Eikenberry Marina Mancuso Enahoro Iboi [...] Abba B Gunnel Face mask use by the general public for limiting the spread of the COVID-19 pandemic is controversial,though increasingly recommended,and the potential of this intervention is not well understood.We develop a compartmental model for assessing the community-wide impact of mask use by the general,asymptomatic public,a portion of which may be asymptomatically infectious.Model simulations,.,,[Show full abstract] vl v:Pull-t�'Xt Article x.010 ,a', Addressing conflicting views on wearing of facemask by the public to combat COVID-19:experiences fr... June 2020 Benjamin Talk Yuen Chan vl v:Pull-t�'Xt Article Making masks for maternity staff May 2020 British Journal of Midwifery Sandra Denicke-Polcher Anna Lawin-O'Brien Despite self-isolation,social distancing and NHS work during the COVID-19 pandemic,Sandra Denicke-Polcher and Anna Lawin-O'Brien found a way to make a joyous difference,connecting the community with healthcare providers on the shop floor Ai,sd mcr= Last Updated:30 Apr2020 Download—the S App Store Company Support Business solutions https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Mode... 18/19 6/15/2020 (PDF)Universal Masking is Urgent in the COVID-19 Pandemic: SEIR and Agent Based Models, Empirical Validation, Policy Recommend... About us Help Center Advertising News Recruiting Careers See all See all 42 References 2 Figures ,I Dote nicad citation Share . https://www.researchgate.net/publication/340933456_Universal_Masking_is_Urgent_in_the_COVI D-19_Pandemic_SEIR_and_Agent_Based_Mode... 19/19 6/15/2020 WHO EMRO Transmission of COVID-19 by asymptomatic cases COVID-19 Health topics 4World Health Organinflon Faoera Mediterranean l ioine Protect yourself Myth busters Questions and answers '..... About COVID...'1 a ''..... ,lews and;r;ed'a updales Situation reports -..-. Infonnati on resources Photo essays Videos O D'I9 e-newsiettei -. Related h,k s COVID-19 News and media updates Transmission of COVID-19 by asymptomatic cases t OVFD-`9 Transmission of COVID-19 by asymptomatic cases Protect yo„rseif Myth busters f u Questions and answers { About COVID-19 - s News and media updates - e Situation reports r onnanon resources Ps re,..af.' Vi hi 1 t !�t Th tii 3 Videos Healthy Ramadan ' n r�r r�i��t '<1ItisJ 1Qrr ` 1 �1 COVID-19 e newsletter - Related links r 11 June 2020-Global research on COVID-19 continues to be conducted,including how the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is transmitted.Current evidence suggests that most transmission occurs from symptomatic people through close contact with others.Accordingly,most recommendations by WHO on personal protective measures(such as use of masks and physical distancing)are based on controlling transmission from symptomatic patients,including patients with mild symptoms who are not easy to identify early on. Available evidence from contact tracing reported by countries suggests that asymptomatically infected individuals are much less likely to transmmit the virus than those who develop symptoms.A subset of studies and data shared by some countries on detailed cluster investigations and contact tracing activities have reported that transmission by asymptomatically-infected individuals are much less likely to transmit the virus than those who develop symptoms. Comprehensive studies on transmission from asymptomatic patients are difficult to conduct,as they require testing of large population cohorts and more data are needed to better understand and quantified the transmissibility of SARS-CoV- 2.WHO is working with countries around the world,and global researchers,to gain better evidence-based understanding of the disease as a whole,including the role of asymptomatic patients in the transmission of the virus. www.emro.who.int/health-topics/corona-virus/transmission-of-covid-19-by-asymptomatic-cases.html 1/1 6/15/2020 Presymptomatic Transmission of SARS-CoV-2—Singapore,January 23—March 16,2020 1 MMWR Centers for Disease Ila,Control and Prevention Morbidity and Mortality Weekly Report (MMWR) Weekly/April 10,2020/69(14);411-415 On April 1,2020, this report was posted online as an MMWR Early Release. Wycliffe E.Wei,MPH',';Zongbin Li,MBBS1;Calvin J.Chiew,MPH';Sarah E.Yong,MMed1; Matthias P.Toh,MMed2,3;Vernon J. Lee,PhD1,3(View author affiliations) View suggested citation Summary MM= What is already known about this topic? AImetri t c: Preliminary evidence indicates the occurrence of presymptomatic transmission of SARS- News(260) BlogCoV-2,based on reports of individual cases in China. 4�as Polic (18) p �# Policy documents What is added by this report? (2) Twitter(3467) Facebook Investigation of all 243 cases of COVID-19 reported in Singapore duringJanuary 23-March (14) 16 identified seven clusters of cases in which res m tomatic transmission is the most Video ddit 2) p y p Video(2) likely explanation for the occurrence of secondary cases. Citations: 37 What are the implications for public health practice? Views: 235,054 The possibility of presymptomatic transmission increases the challenges of containment Views equals page views measures.Public health officials conducting contact tracing should strongly consider plus PDFdownloads including a period before symptom onset to account for the possibility of presymptomatic r® transmission.The potential for presymptomatic transmission underscores the importance of social distancing,including the avoidance of congregate settings,to reduce COVID-19 spread. Figure Presymptomatic transmission of SARS-CoV-2,the virus that causes coronavirus disease 2019 References (COVID-19),might pose challenges for disease control.The first case of COVID-19 in Singapore was detected on January 23,2020,and by March 16,a total of 243 cases had been confirmed, f including 157 locally acquired cases.Clinical and epidemiologic findings of all COVID-19 cases in Singapore through March 16 were reviewed to determine whether presymptomatic transmission might have occurred. Presymptomatic transmission was defined as the transmission of SARS-CoV-2 from an infected person(source patient)to a secondary patient before the source patient developed symptoms,as ascertained by exposure and symptom PDF IM [150K] onset dates,with no evidence that the secondary patient had been exposed to anyone else with COVID-19.Seven COVID-19 epidemiologic clusters in which presymptomatic transmission likely occurred were identified,and 10 such cases within these clusters accounted for 6.4%of the 157 locally acquired cases. In the four clusters for which the date of exposure could be determined,presymptomatic transmission occurred 1-3 days before symptom onset in the presymptomatic source patient.To account for the possibility of presymptomatic transmission,officials developing contact tracing protocols should strongly consider including a period before symptom onset. Evidence of presymptomatic transmission of SARS-CoV-2 underscores the critical role social distancing,including avoidance of congregate settings,plays in controlling the COVID-19 pandemic. Early detection and isolation of symptomatic COVID-19 patients and tracing of close contacts is an important disease containment strategy; however,the existence of presymptomatic or asymptomatic transmission would present difficult challenges to contact tracing.Such transmission modes have not been definitively documented for COVID-19,although cases of presymptomatic and asymptomatic transmissions have been reported in China(1,2)and possibly occurred in a nursing https://www.cdc.gov/mmwr/volumes/69/wr/mm6914el.htm 1/6 6/15/2020 Presymptomatic Transmission of SARS-CoV-2—Singapore,January 23—March 16,2020 1 MMWR facility in King County,Washington(3). Examination of serial intervals(i.e.,the number of days between symptom onsets in a primary case and a secondary case)in China suggested that 12.6%of transmission was presymptomatic(2).COVID-19 cases in Singapore were reviewed to determine whether presymptomatic transmission occurred among COVID-19 clusters. The surveillance and case detection methods employed in Singapore have been described(4). Briefly,all medical practitioners were required by law to notify Singapore's Ministry of Health of suspected and confirmed cases of COVID-19.The definition of a suspected case was based on the presence of respiratory symptoms and an exposure history.Suspected cases were tested, and a confirmed case was defined as a positive test for SARS-CoV-2,using laboratory-based polymerase chain reaction or serologic assays(5).All cases in this report were confirmed by polymerase chain reaction only.Asymptomatic persons were not routinely tested,but such testing was performed for persons in groups considered to be at especially high risk for infection,such as evacuees on flights from Wuhan,China(6),or families that experienced high attack rates. Patients with confirmed COVID-19 were interviewed to obtain information about their clinical symptoms and activity history during the 2 weeks preceding symptom onset to ascertain possible sources of infection.Contact tracing examined the time from symptom onset until the time the patient was successfully isolated to identify contacts who had interactions with the patient.All contacts were monitored daily for their health status,and those who developed symptoms were tested as part of active case finding. Clinical and epidemiologic data for all 243 reported COVID-19 cases in Singapore during January 23-March 16 were reviewed. Clinical histories were examined to identify symptoms before,during,and after the first positive SARS-CoV-2 test. Records of cases that were epidemiologically linked(clusters)were reviewed to identify instances of likely presymptomatic transmission.Such clusters had clear contact between a source patient and a patient infected by the source(a secondary patient),had no other likely explanations for infection,and had the source patient's date of symptom onset occurring after the date of exposure to the secondary patient who was subsequently infected.Symptoms considered in the review included respiratory,gastrointestinal(e.g.,diarrhea),and constitutional symptoms. In addition,the source patient's exposure had to be strongly attributed epidemiologically to transmission from another source.This reduced the likelihood that an unknown source was involved in the cases in the cluster. Top Seven Clusters of COVID-19 Cases Suggesting Presymptomatic Transmission Investigation of COVID-19 cases in Singapore identified seven clusters(clusters A-G)in which presymptomatic transmission likely occurred.These clusters occurred during January 19-March 12,and involved from two to five patients each(Figure).Ten of the cases within these clusters were attributed to presymptomatic transmission and accounted for 6.4%of the 157 locally acquired cases reported as of March 16. Cluster A.A woman aged 55 years(patient Al)and a man aged 56 years(patient A2)were tourists from Wuhan,China,who arrived in Singapore on January 19.They visited a local church the same day and had symptom onset on January 22(patient Al)and January 24(patient A2).Three other persons,a man aged 53 years(patient A3),a woman aged 39 years(patient A4), and a woman aged 52 years(patient A5)attended the same church that day and subsequently developed symptoms on January 23,January 30,and February 3,respectively.Patient A5 occupied the same seat in the church that patients Al and A2 had occupied earlier that day(captured by closed-circuit camera)(5). Investigations of other attendees did not reveal any other symptomatic persons who attended the church that day. Cluster B.A woman aged 54 years(patient B1)attended a dinner event on February 15 where she was exposed to a patient with confirmed COVID-19.On February 24,patient B1 and a woman aged 63 years(patient B2)attended the same singing class.Two days later(February 26),patient B1 developed symptoms; patient B2 developed symptoms on February 29. Cluster C.A woman aged 53 years(patient Cl)was exposed to a patient with confirmed COVID-19 on February 26 and likely passed the infection to her husband,aged 59 years(patient C2)during her presymptomatic period;both patients developed symptoms on March 5. Cluster D.A man aged 37 years(patient D1)traveled to the Philippines during February 23-March 2,where he was in contact with a patient with pneumonia who later died. Patient D1 likely transmitted the infection to his wife(patient D2),aged 35 years,during his presymptomatic period.Both patients developed symptoms on March 8. https://www.cdc.gov/mmwr/volumes/69/wr/mm6914el.htm 2/6 6/15/2020 Presymptomatic Transmission of SARS-CoV-2—Singapore,January 23—March 16,2020 1 MMWR Cluster E.A man aged 32 years(patient E1)traveled to Japan during February 29-March 8,where he was likely infected,and subsequently transmitted the infection to his housemate,a woman aged 27 years(patient E2),before he developed symptoms. Both developed symptoms on March 11. Cluster F.A woman aged 58 years(patient F1)attended a singing class on February 27,where she was exposed to a patient with confirmed COVID-19.She attended a church service on March 1,where she likely infected a woman aged 26 years (patient F2)and a man aged 29 years(patient F3),both of whom sat one row behind her.Patient F1 developed symptoms on March 3,and patients F2 and F3 developed symptoms on March 3 and March 5,respectively. Cluster G.A man aged 63 years(patient G1)traveled to Indonesia during March 3-7.He met a woman aged 36 years(patient G2)on March 8 and likely transmitted SARS-CoV-2 to her; he developed symptoms on March 9,and patient G2 developed symptoms on March 12. Investigation of these clusters did not identify other patients who could have transmitted COVID-19 to the persons infected. In four clusters(A,B,F,and G),presymptomatic transmission exposure occurred 1-3 days before the source patient developed symptoms. For the remaining three clusters(C,D,and E),the exact timing of transmission exposure could not be ascertained because the persons lived together,and exposure was continual. Top Discussion This investigation identified seven clusters of COVID-19 in Singapore in which presymptomatic transmission likely occurred. Among the 243 cases of COVID-19 reported in Singapore as of March 16, 157 were locally acquired; 10 of the 157(6.4%) locally acquired cases are included in these clusters and were attributed to presymptomatic transmission.These findings are supported by other studies that suggest that presymptomatic transmission of COVID-19 can occur(1-3).An examination of transmission events among cases in Chinese patients outside of Hubei province,China,suggested that 12.6%of transmissions could have occurred before symptom onset in the source patient(3). Presymptomatic transmission might occur through generation of respiratory droplets or possibly through indirect transmission.Speech and other vocal activities such as singing have been shown to generate air particles,with the rate of emission corresponding to voice loudness(7).News outlets have reported that during a choir practice in Washington on March 10,presymptomatic transmission likely played a role in SARS-CoV-2 transmission to approximately 40 of 60 choir members.* Environmental contamination with SARS-CoV-2 has been documented(8),and the possibility of indirect transmission through fomites by presymptomatic persons is also a concern.Objects might be contaminated directly by droplets or through contact with an infected person's contaminated hands and transmitted through nonrigorous hygiene practices. The possibility of presymptomatic transmission of SARS-CoV-2 increases the challenges of COVID-19 containment measures, which are predicated on early detection and isolation of symptomatic persons.The magnitude of this impact is dependent upon the extent and duration of transmissibility while a patient is presymptomatic,which,to date,have not been clearly established. In four clusters(A,B,F,and G),it was possible to determine that presymptomatic transmission exposure occurred 1-3 days before the source patient developed symptoms.Such transmission has also been observed in other respiratory viruses such as influenza. However,transmissibility by presymptomatic persons requires further study. The findings in this report are subject to at least three limitations. First,although these cases were carefully investigated,the possibility exists that an unknown source might have initiated the clusters described.Given that there was not widespread community transmission of COVID-19 in Singapore during the period of evaluation and while strong surveillance systems were in place to detect cases,presymptomatic transmission was estimated to be more likely than the occurrence of unidentified sources. Further,contact tracing undertaken during this period was extensive and would likely have detected other symptomatic cases.Second,recall bias could affect the accuracy of symptom onset dates reported by cases,especially if symptoms were mild,resulting in uncertainty about the duration of the presymptomatic period. Finally,because of the nature of detection and surveillance activities that focus on testing symptomatic persons,underdetection of asymptomatic illness is expected. Recall bias and interviewer bias(i.e.,the expectation that some symptoms were present,no matter how mild), could have contributed to this. The evidence of presymptomatic transmission in Singapore,in combination with evidence from other studies(9,10)supports the likelihood that viral shedding can occur in the absence of symptoms and before symptom onset.This study identified seven clusters of cases in which presymptomatic transmission of COVID-19 likely occurred; 10(6.4%)of such cases included in thaca rliictarc to/ara amnnv tha 1 S7 InralIx/arniiirarl racac rannrtari in Cinvannra ac of KAarrh 1 H (nntainmant maaairac https://www.cdc.gov/mmwr/volumes/69/wr/mm6914el.htm 3/6 6/15/2020 Presymptomatic Transmission of SARS-CoV-2—Singapore,January 23-March 16,2020 1 MMWR should account for the possibility of presymptomatic transmission by including the period before symptom onset when conducting contact tracing.These findings also suggest that to control the pandemic it might not be enough for only persons with symptoms to limit their contact with others because persons without symptoms might transmit infection. Finally,these findings underscore the importance of social distancing in the public health response to the COVID-19 pandemic,including the avoidance of congregate settings. Top Corresponding author:Vernon J. Lee,Vernon_Lee@moh.gov.sg. Top 'Ministry of Health,Singapore;2National Centre for Infectious Diseases,Singapore;3Saw Swee Hock School of Public Health, Singapore. Top All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed. Top *https://www.latimes.com/world-nation/story/2020-03-29/coronavirus-choir-outbreak[Z'. Top References 1. Qian G,Yang N,Ma AHY,et al.A COVID-19 Transmission within a family cluster by presymptomatic infectors in China. Clin Infect Dis 2020. Epub March 23,2020.CrossRef P", PubMed Z 2. Du Z,Xu X,Wu Y,Wang L,Cowling BJ,Meyers LA.Serial interval of COVID-19 among publicly reported confirmed cases. Emerg Infect Dis 2020.Epub March 19,2020.CrossRef P", PubMed Z 3. Kimball A,Hatfield KM,Arons M,et al.Asymptomatic and presymptomatic SARS-CoV-2 infections in residents of a long- term care skilled nursing facility—King County,Washington,March 2020. MMWR Morb Mortal Wkly Rep 2020. Epub March 27,2020.CrossRef Z 4. Ng Y,Li Z,Chua YX,et al.Evaluation of the effectiveness of surveillance and containment measures for the first 100 patients with COVID-19 in Singapore January 2-February 29,2020.MMWR Morb Mortal Wkly Rep 2020;69:307-11. CrossRef P', PubMed Z 5. Pung R,Chiew C],Young BE,et al.;Singapore 2019 Novel Coronavirus Outbreak Research Team. Investigation of three clusters of COVID-19 in Singapore: implications for surveillance and response measures. Lancet 2020;395:1039-46. CrossRef P', PubMed Z 6. Ng O-T,Marimuthu K,Chia P-Y,et al.SARS-CoV-2 infection among travelers returning from Wuhan,China.N Engl J Med 2020.Epub March 12,2020.CrossRef Pli PubMed Z 7.Asadi S,Wexler AS,Cappa CD,Barreda S,Bouvier NM,Ristenpart WD.Aerosol emission and superemission during human speech increase with voice loudness.Sci Rep 2019;9:2348.CrossRef L, PubMed L, 8. Ong SWX,Tan YK,Chia PY,et al.Air,surface environmental,and personal protective equipment contamination by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)from a symptomatic patient.JAMA 2020.Epub March 4,2020. CrossRef P', PubMed Z 9. Hu Z,Song C,Xu C,et al.Clinical characteristics of 24 asymptomatic infections with COVID-19 screened among close contacts in Nanjing,China.Sci China Life Sci 2020. Epub March 4,2020.CrossRef Z PubMed Z 10.Wang Y,Liu Y,Liu L,Wang X,Luo N,Ling L.Clinical outcome of 55 asymptomatic cases at the time of hospital admission infected with SARS-Coronavirus-2 in Shenzhen,China.J Infect Dis 2020.Epub March 17,2020.CrossRef D-1 PubMed D" Top FIGURE.Seven COVID-19 clusters with evidence of likely presymptomatic SARS-CoV-2 k to! transmission from source patients to secondary patients — Singapore,January 19-March 12,2020 Gates of likely transmission,symptom onset,and rather exposure Jan Fees Cluster A 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 1 2 3 Symptoms Patient Al Fever Patient A2 Fever https://www.cdc.gov/mmwr/volumes/69/wr/mm6914el.htm 4/6 6/15/2020 Presymptomatic Transmission of SARS-CoV-2—Singapore,January 23—March 16,2020 1 MMWR raven:tAi never Patient A4 Fever cough Patient AS Fever,5are throat Dates of likely transmission,symptom onset,and other exposure Feb Cluster B 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Symptoms Patient8l Cough,headache,myalgia Patient B2 Fever,cough,headache,myalgia Dates of likely transmission,symptom onset, and other exposure Feb Mar ClusterC 26 27 28 1 29 1 2 1 3 4-T-s Symptoms Patient C I Itchy throat,chills Patient C2 Cough Im IN Dates of likely transmission,symptom onset,and other exposure Feb Mar Cluster D 23 24 25 26 27 28 1 29 1 2 1 3 4 5 6 7 8 Symptoms Patient DI Cough,blocked nose Patient D2 Fever,sore throat,sneezing Dates of likely transmission,symptom onset and other exposure Feb Mar Cluster E 29 1 2 3 4 5 6 7 8 10 11 Symptoms Patient El Fever Patient E2 Cough Dates of likely transmission,symptom onset, and other exposure Feb Mar Cluster F 27 28 29 1 2 3 4 5 Symptoms Patient F1 Sore throat,blocked nose Patient F2 Cough Patient F3 Cough,runny nose,sore throat myalgia Dates of likely transmission,symptom onset, and other exposure Mar ClusterG 3 4 5 1 6 7 8 1 9 10 11 1 12 Symptoms Patient G I Fever Patient G2 61 Sore throat it Source patient Other exposure(clusters B,C and F:known COVID-19 case;cluster A:unknown exposure in Wuhan,China;cluster D:patient in Philippines with pneumonia;cluster E:unknown exposure in Japan;cluster G:unknown exposure in Indonesia) Likely period of transmission from source patient to secondary patients Symptom onset date https://www.cdc.gov/mmwr/volumes/69/wr/mm6914el.htm 5/6 6/15/2020 Presymptomatic Transmission of SARS-CoV-2—Singapore,January 23—March 16,2020 1 MMWR Top Suggested citation for this article:Wei WE,Li Z,Chiew CJ,Yong SE,To MP,Lee VJ. Presymptomatic Transmission of SARS- CoV-2—Singapore,January 23-March 16,2020.MMWR Morb Mortal Wkly Rep 2020;69:41 1-415. DOI: http://dx.doi.org/10.15585/mmwr.mm6914el Z. MMWR and Morbidity and Mortality Weekly Report are service marks of the U.S.Department of Health and Human Services. Use of trade names and commercial sources is for identification only and does not imply endorsement by the U.S.Department of Health and Human Services. References to non-CDC sites on the Internet are provided as a service to MMWR readers and do not constitute or imply endorsement of these organizations or their programs by CDC or the U.S.Department of Health and Human Services.CDC is not responsible for the content of pages found at these sites.URL addresses listed in MMWR were current as of the date of publication. All HTML versions of MMWR articles are generated from final proofs through an automated process.This conversion might result in character translation or format errors in the HTML version.Users are referred to the electronic PDF version(https://www.cdc.gov/mmwr)and/or the original MMWR paper copy for printable versions of official text,figures,and tables. Questions or messages regarding errors in formatting should be addressed to mmwrq@cdc.gov. Page last reviewed:April 9,2020 https://www.cdc.gov/mmwr/volumes/69/wr/mm6914el.htm 6/6 6/15/2020 Covid-19:four fifths of cases are asymptomatic,China figures indicate I The BMJ Intended for healthcare professionals News Covid-19: four fifths of cases are asymptomatic, China figures indicate BMJ 2020;369 doi:https://doi.org/10.1136/bmj.m1375(Published 02 April 2020)Cite this as:BMJ 2020;369:ml375 Article • Related content • Metrics • Responses • Peer review • G Michael Day Author affiliations New evidence has emerged from China indicating that the large majority of coronavirus infections do not result in symptoms. Chinese authorities began publishing daily figures on 1 April on the number of new coronavirus cases that are asymptomatic,with the first day's figures suggesting that around four in five coronavirus infections caused no illness.Many experts believe that unnoticed,asymptomatic cases of coronavirus infection could be an important source of contagion. A total of 130 of 166 new infections(78%)identified in the 24 hours to the afternoon of Wednesday 1 April were asymptomatic,said China's National Health Commission.And most of the 36 cases in which patients showed symptoms involved arrivals from overseas,down from 48 the previous day,the commission said. China is rigorously testing arrivals from overseas for fear of importing a fresh outbreak of covid-19. Tom Jefferson,an epidemiologist and honorary research fellow at the Centre for Evidence-Based Medicine at the University of Oxford,said the findings were"very,very important."He told The BMJ,"The sample is small,and more data will become available.Also,it's not clear exactly how these cases were identified.But let's just say they are generalisable.And even if they are 10%out, then this suggests the virus is everywhere.If—and I stress,if—the results are representative,then we have to ask,'What the hell are we locking down for? Jefferson said that it was quite likely that the virus had been circulating for longer than generally believed and that large swathes of the population had already been exposed. Users of Chinese social media have expressed fears that carriers with no symptoms could be spreading the virus unknowingly,especially now that infections have subsided and authorities have eased curbs on travel for people in previous hotspots in the epidemic. Zhong Nanshan,a senior medical adviser to the Chinese government,said that asymptomatic infections would not be able to cause another major outbreak of covid-19 if such people were kept in isolation.Officials have said this is usually for 14 days. Nanshan said that once asymptomatic infected people were identified,they and their contacts would be isolated and kept under observation. Citing classified data,the South China Morning Post said that China had already found more than 43 000 cases of asymptomatic infection through contact tracing. The latest findings seem to contradict a World Health Organization report in February that was based on covid-19 in China.This suggested that"the proportion of truly asymptomatic infections is unclear but appears to be relatively rare and does not appear to be a major driver of transmission."1 But since that WHO report other researchers,including Sergio Romagnani,a professor of clinical immunology at the University of Florence,have said they have evidence that most people infected by the virus do not show symptoms.Romagnani led the research that showed that blanket testing in a completely isolated village of roughly 3000 people in northern Italy saw the number of people with covid-19 symptoms fall by over 90%within 10 days by isolating people who were symptomatic and those who were asymptomatic.2 In an article on the website of the Centre for Evidence-Based Medicine,Jefferson and Carl Heneghan,director of the centre and editor of BMJ EBM,write,"There can be little doubt that covid-19 may be far more widely distributed than some may believe.Lockdown is going to bankrupt all of us and our descendants and is unlikely at this point to slow or halt viral circulation as the genie is out of the bottle. "What the current situation boils down to is this:is economic meltdown a price worth paying to halt or delay what is already amongst us?"3 This article is made freely available for use in accordance with BMSs website terms and conditions for the duration of the covid-19 pandemic or until otherwise determined by BMJ.You may use, download and print the article for any lawful,non-commercial purpose(including text and data mining)provided that all copyright notices and trade marks are retained. httpL.//bmj.com/coronavirus/usaga References 1. World Health Organization.Report of the WHO-China Joint Mission on coronavirus disease 2019(COVID-19).2020.https:/Avvw.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19- final-report.pdf. 2.'Day M.Covid-19:identifying and isolating asymptomatic people helped eliminate virus in Italian village.BM✓2020,368:m1165.doi:10.1136/bmj.m1165 pmid:32205334 FREE Full Text Google Scholar 3.'Jefferson T,Hennegan C.Covid-19—The tipping point?Mar 2020.Centre for Evidence-Based Medicine.Mar 2020.https./Mmwcebm.net/2020/03/covid-19-the-tipping-point. View Abstract A-&;-1—4-1— https://www.bmj.com/content/369/bmj.ml 375 1/3 6/15/2020 Covid-19:four fifths of cases are asymptomatic,China figures indicate The BMJ 4Print FlAlerts&updates Article alerts Please note:your email address is provided to the journal,which may use this information for marketing purposes. 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HONJE ABOUT H11r) 01 5 1;f; f�rj),Frk"Ij r 1j,; P11 A,,I j j r Et I A B -:c, G,L Llf,H -� - N INFECTIOUS DESE COVID-19 UPDATE ASES S w Influenza SARS-G.V-20)R='jj7.-7 PUBLISHED:10 FEBRUARY 2020 iyL w Avian influenza A(H7N 2020/06/12 9) Field Briefing: Diamond Princess COVI -1 9 Cases <Rpid r,p,rt>0utb w Measles Background: f--I d CGOVID-19) F COVID-19 A cruise ship,named the Diamond Princess,had travel that originated in Yokohama on 20 January and ,ichip included stops in Japan(Kagoshima),Hong Kong,Vietnam,Taiwan and Japan(Okinawa),before arriving Ig...ki City®urelirnirra back in Yokohama on 3 February.During this time,a passenger who disembarked on 25 January in y interi ru re rL.-rt Hong Kong,has presented with cough since 44 23 Jan and was confirmed positive for Novel 2020/06/03 BASIC RESEARCH coronavirus on 1 February.The Japanese government requested that the Diamond Princess stay at port,with no passengers or crew disembarking,in Yokohama when it arrived on 3 February.During 3_4 Descriptive February,health status of all passengers and crew members were checked by questionnaire by f 516 confirmed case Achievement quarantine officers,and respiratory specimens were taken from symptomatic passengers,crew,and f v.vd--n-drus i their close contacts to test for Novel coronavirus.On 5 February,a lab-confirmed case of COVID-19 n—t-b-,reported by the Laboratory manuals fo led to the quarantine of the Diamond Princess for 14 days beginning at lam,with passengers requested. national epidemiological r pathogen detection "int- to stay in their cabins.As of 5 February,there was a total of 3711 individuals on board the Diamond 7 diseases( From Laboratories Princess,with 2666 passengers and 1045 crew members. -and active ggi-I Annual Report Quarantine Measures: �f M...h 23,2020) At the beginning of the quarantine period,crew members were provided with personal protective 2020/04/09 equipment(PPE)and instructed on appropriate IPC practices.On 7 February,passengers were Descriptive o International cooperati provided thermometers for self-monitoring of body temperature,with instructions on calling a"Fever Call Center",if they had a fever above 37.5C.Passengers who developed fever were referred to the he y f 287 confirmed.. on , medical team in charge and were tested for Novel coronavirus.Passengers who developed serious -Afl--ve rt.d--viru,bv them illness,including non-COVID-1 9 morbidities,were referred the ship's Medical Center,which provided ti—I epidemiological essential health services.Those passengers with lab-confirmed COVID-19were disembarked and --ill.—of infection SURVEILLANCE transferred to an isolation ward at healthcare facilities.Their calbirmates were defined as"close .dis.... contacts"and were therefore tested.If positive,they were also confirmed as a case and disembarked D)..d active apidemiol s to a healthcare facility.If they tested negative,they remained on board but with a 14-day quarantine o9il surveillance Cgs Infectious Diseases We period reset after the last contact with the confirmed case.All crew and healthcare staff onboard the of March 9,2020) ekly Report(IDWR) Diamond Princess were instructed to follow international guidance on infection prevention and control. 2020/03/17 To maintain operations of the ship,some crew continued to perform essential,limited services while Infectious Agents Sury the ship remained in quarantine.This led to those crew members not remaining fully isolated,in the Descriptive eillance Report(IASR) same manner as passengers,during the quarantine period. y.of 112 confirmed c. National Surveillance o Data Collection: rf..ti.di......(COVI f Vaccine-preventable pn,ted by=.Lh= Diseases(SeroEpi) Initially,only symptomatic cases and close contacts were beingtested for COVID-19.This was e r.ti...I epidemiolcgic changed on 11 February,due to the expansion of laboratory capacity,with quarantine officers aI ur-ill,-, f infect Japan Nosocomial Infe systematically collecting respiratory specimens from all passengers by age group,starting with those 80 u.di-....(NESID) ctions Surveillance WA years old and older as well as individuals with co-morbidities,such as diabetes or a heart condition. ysteen and active�,pjd NIS) Respiratory specimens collected were tested via PCR for confirmation of Novel coronavirus. n1ij.=lcgi..l investigation Epidemiological data collected was initially limited due to the emergency nature of the quarantine and (..of February 24, included data on onset of symptoms,date of lab confirmation,and close contacts.A confirmed case of 2020/03/10 COVID-1 9,for this report,is anyone,passenger or crew,who had a positive PCR test for Novel INFORMATION coronavirus,independent of their symptom presentation.In most cases,the"population on board," M.-M f.,Active.EpLd.e refers to the 3,711 passenger and crew aboard Diamond Princess on 5 February. miolcgical Surveillance of Paticrrt.evith Novel w Disclosure Preliminary Results: (1--,iru.1,.ft1(P rovisi—I Version) r Lectures and Open-ca As of 18 February,there have been 531 confirmed cases(14.3%of all individuals on board on 5 2020/02/27 mpus February),including 65 crew and 466 passengers.A total 2404 respiratory specimens were tested,and 542 were positive(22.5),including double tests.Among confirmed COVID-1 9 cases with recorded G...of Fir.t Human-to w Attention symptom onset(n=184),there were 33(18%)with onset dates before 6 February,which was the first -H-1nftl f No full day of quarantine,and 151(82%)with onset dates on or after the 6th.A total 255(48%)of the 1 coronavirus in J.Pi confirmed cases were asymptomatic when the respiratory specimen was collected.Of these,8 were n crew and 247 were passengers.(Information on development of symptoms after disembarkation of 2020/02/26 asymptomatic confirmed cases is not currently available.)A total 23 passengers with reported onset dates were confirmed after another passenger in the same cabin had been confirmed.From 13 Fuld BHfl,,g:Diamond to now,81%of cases among confirmed passengers or crew with reported onset dates(n-22) Princess GOVID-19 Ga. -,20 Feb Update occurred in crew(n=l 3)or passengers from cabins with a previously confirmed case(n=5). 2020/02/21 Preliminary Conclusions: Ap Based on the number of confirmed cases by onset date,there is clear evidence that substantial st from National Irstitut transmission of COVID-1 9 had been occurring prior to implementation of quarantine on the Diamond e of Iff-ti...Di.... Princess on 5 February(see also febrile patient visits to the on-board clinic below).The decline in the -A..-p mL number of confirmed cases,based on reported onset dates,implies that the quarantine intervention 2020/02/21 was effective in reducing transmission among passengers.Transmission toward the end of the quarantine period,which is scheduled to end for most passengers on 19 Feb,appears to have occurred Infection control f.,ro mostly among crew or within passenger cabins.It should be noted that due to the nature of the ship, VID-19 individual isolation of all those aboard was not possible.Sharing of cabins was necessary,and some 2020/02/21 crew had to continue to perform essential duties for the functioning of the vessel with passengers Field Briefing:Diamond aboard. Princess GOVID-19 G.. Recent confirmations of asymptomatic cases can be explained by the systematic testing of passengers S�L that began around 14 Feb.Although some of these cases may have been secondary cases within a 2020/02/18 given cabin,it is difficult to know when transmission occurred.They may have been infected before the quarantine began.Nevertheless,these asymptomatic cases have been disembarked and their Descriptive 9. calbirmates have been defined as close contacts with their 14-day isolation reset on the day the y_gf 12 Confirmed 2019- asymptomatic case was disembarked.The systematic testing of asymptomatic cases was useful in N1 0--viru,(2019 screening these persons before allowing them to disembark. G v)case,; "J.WUL (A.of 3 February 2020 Actions/Guidance: 2020/02/13 Those persons(mostly passengers)who have completed the 14-day quarantine,have not tested Reporting Grit.ri.of N. positive,and pass a medical check on the 14th day,will be disembarked on the 1 9th -I G....dr-2019 4.f ggtiin Japan Those individuals who were in contact with a confirmed case will be put in isolation until they complete 2020/02/09 the 14-day period beginning after the last day of their suspected contact with a case.This includes a large proportion of the crew members of the Diamond Princess.The crew performed essential tasks E-1-ti-of the Curren that allowed the quarantine to occur successfully for 14 days and should be appreciated for their t Situation of GOVID-1 service. 2,and the https://www.niid.go.jp/niid/en/2019-ncov-e/9407-covid-dp-fe-Ol.html 1/3 6/15/2020 Field Briefing: Diamond Princess COVID-19 Cases As the persons aboard were exposed to a high-risk environment for a prolonged period,all persons who of survellla—and Med disembark should be careful about the health conditions for the time being and immediately report to a ca�I Syster,,, in Jap® public health center if they develop symptoms. 2020/02/07 Ceronavirus disease(C Percent of persons aboard who were confirmed with COVID-19 by age group and OVID-19) symptom status at the time of specimen collection. 2020/01/10 Age Symptomatic Asymptomatic Total Persons CP ] confirmed confirmed confirmed aboard on 5 group cases (%) cases (%) cases (%) February 2020-02-21-Field Brief Lig:Diamond Princess GCS VID-19 Cases,20 Feb Up 00-09 0(0) 1(6) 1(6) 16 date 10-19 1(4) 1(4) 2(9) 23 20-29 18(5) 20) 20(6) 347 30-39 18(4) 50) 23(5) 429 40-49 18(5) 7(2) 25(8) 333 50-59 27(7) 22(6) 4902) 398 60-69 73(8) 56(6) 12904) 924 70-79 92(9) 1360 3) 228(22) 1015 80-89 2703) 2502) 52(24) 215 90-99 208) 0(0) 208) 11 Total 276(7) 255(7) 531(14) 3711 Number of confirmed GOVID-19 cases with reported onset dates, by onset date, aboard Diamond Princess, 6 - 17 February 2020 (n=151) 35 30 25 0 Passengers a Crew 0 20 1, .Q z 10 . 6-Feb 7'-Feb 8-Feb 94eb 10--eb 11-Feb 12-Feb 13-Feb 34Feb 1F-Feb Onset Date Febrile Patients, by date of clinic visit, Diamond Princess clinic, 19 Jan - 2 Feb 2020 (n=79) 14 N 12 Hang Kang-reported case disembarked '-�-- 10 t u s I- v t 0 6 First day cf voyage o a yam �c ,ac tir �ror y° �a yr sar �m e� ke`p kvns a4V 1vt v ary ry � tia 1y ti\ 1� tig ia' 'sto �1 1 L Date of clinic visit Characteristics of COVID-19 Cases with reported on-set dates of 6 - 17 Feb 2020 (n=151)*. Date of Onset Passengers from cabins with Crew Passengers (n cases) another confirmed case (%) 17 Feb(0) 0 0 0 16 Feb(0) 0 0 0 15 Feb(1) 1 0 0 14 Feb(5) 4 1 1(100%)[01 13 Feb(16) 8 8 4(50%)[21 12 Feb(12) 7 5 0(00%)[21 11 Feb(18) 7 11 3(27%) 1 10 Feb(10) 3 7 3(43%) 1 9 Feb(24) 5 1 19 6(32%) 9 8 Feb(18) 1 2 1 16 1(6%) 3 https://www.niid.go.jp/niid/en/2019-ncov-e/9407-covidAlo-fe-01.html 2/3 6/15/2020 Field Briefing: Diamond Princess COVID-19 Cases 7 Feb(31) 2 29 4(14%)[101 6 Feb(16) 1 15 1(7%)[6] Total 40 1 ill 1 23 (21%) [341 *The total number of cases in this table(n-151)is Me total number of cases with known onset dates. Note,tl7e number in brackets represents the number ofadditional confirmed cases in the same cabin with unknown onset date. Corrigendum: • The denominator in the table Characteristics of COVID-19 Cases with reported on-set dates of 6-17 Feb 2020(n=53)-was incorrect upon publication.This Briefing has been updated on 20 Feb to reflect the accurate number at time of publishing(n=151). • In Background,a passenger who disembarked on 25 January in Hong Kong has presented with coug h since 19 Jan was incorrect upon publication.This parson has been coughed since 23 Jan. 1`ERMS WUSF „,yr ;r.:1.,t https://www.niid.go.jp/niid/en/2019-ncov-e/9407-covid-dp-fe-01.html 3/3 6/15/2020 COVID-19 Provisional Counts-Weekly Updates by Select Demographic and Geographic Characteristics 10Centers for Disease ,Control and Prevention National Center for Health Statistics Weekly Updates by Select Demographic and Geographic Characteristics Provisional Death Counts for Coronavirus Disease (COVID-19) Contents Daily Updates ofTotaIs by Week and State Weekly Updates by Select Demographic and Geographic Characteristics Excess Deaths Associated with COVID-19 Technical Notes Updated:June 10,2020 Note:Provisional death counts are based on death certificate data received and coded by the National Center for Health Statistics as of June 10,2020.Death counts are delayed and may differ from other published sources(see Technical Notes).Counts will be updated every Wednesday by 5pm.Additional information will be added to this site as available. List of Topics 1.Age and sex 2. Race and Hispanic origin byjurisdiction and by age 3. Place of death 4. Comorbidities 5. Excess deaths 6. State and county data files Age and sex Table 1 has death counts of COVID-19 and select causes of death by sex and age group for the United States. For data on sex and age at the state level � cij�ki ere to doWr ioad�. For data on sex and age by week,�pClick hereto download. https://www.cdc.gov/nchs/nvss/vsrr/covid weeklyfindex.htm 1/4 6/15/2020 COVID-19 Provisional Counts-Weekly Updates by Select Demographic and Geographic Characteristics Comorbidities Table 4 shows the types of health conditions and contributing causes mentioned in conjunction with deaths involving coronavirus disease 2019(COVID-19).For 7%of the deaths,COVID-19 was the only cause mentioned. For deaths with conditions or causes in addition to COVID-19,on average,there were 2.5 additional conditions or causes per death.The number of deaths with each condition or cause is shown for all deaths and by age groups.For data on comorbidity, (;}-Click here to�download�. Excess deaths See the NCHS Excess Deaths Data Visualization. This data visualization presents data on weekly counts of all-cause mortality byjurisdiction of occurrence.Counts of deaths in the most recent weeks are compared with historical trends to determine whether the number of deaths in recent weeks is significantly higher than expected. State and County Data Files Weekly Counts of Deaths by State and Select Causes • Final data for 2014-2018 0-Weekly counts of leading causes of death based on final underlying cause mortality data for years 2014-2018. • Provisional data for 2019-2020 0-Weekly counts of leading causes of death based on provisional underlying cause mortality data for 2019-2020,updated weekly. Provisional COVID-19 Death Counts in the United States by County • This file includes deaths caused by COVID-19(coded to ICD-10 code U07.1)and total deaths per county.Counties included in this table had 10 or more COVID-19 deaths at the time of analysis. Understanding the Numbers: Provisional Death Counts and COVID-19 Provisional death counts deliver the most complete and accurate picture of lives lost to COVID-19. They are based on death certificates, which are the most reliable source of data and contain information not available anywhere else, including comorbid conditions,race and ethnicity,and place of death. How it Works The National Center for Health Statistics(NCHS)uses incoming data from death certificates to produce provisional COVID-19 death counts.These include deaths occurring within the 50 states and the District of Columbia. NCHS also provides summaries that examine deaths in specific categories and in greater geographic detail,such as deaths by county and by race and Hispanic origin. COVID-19 deaths are identified using a new ICD-10 code.When COVID-19 is reported as a cause of death-or when it is listed as a"probable"or"presumed"cause—the death is coded as U07.1.This can include cases with or without laboratory confirmation. Why These Numbers are Different Provisional death counts may not match counts from other sources,such as media reports or numbers from county health departments.Counts by NCHS often track 1-2 weeks behind other data. • Death certificates take time to be completed.There are many steps to filling out and submitting a death certificate. https://www.cdc.gov/nchs/nvss/vsrr/covid_weeklylndex.htm 3/4 6/15/2020 COVID-19 Provisional Counts-Weekly Updates by Select Demographic and Geographic Characteristics Waiting for test results can create additional delays. • States report at different rates.Currently,63%of all U.S.deaths are reported within 10 days of the date of death,but there is significant variation between states. • It takes extra time to code COVID-19 deaths.While 80%of deaths are electronically processed and coded by NCHS within minutes,most deaths from COVID-19 must be coded by a person,which takes an average of 7 days. • Other reporting systems use different definitions or methods for counting deaths. Things to know about the data Provisional counts are not final and are subject to change.Counts from previous weeks are continually revised as more records are received and processed. Provisional data are not yet complete.Counts will not include all deaths that occurred during a given time period, especially for more recent periods. However,we can estimate how complete our numbers are by looking at the average number of deaths reported in previous years. Death counts should not be compared across states.Some states report deaths on a daily basis,while other states report deaths weekly or monthly.State vital record reporting may also be affected or delayed by COVID-19 related response activities. For more detailed technical information,visit the Provisional Death Counts for Coronavirus Disease(COVID-19)Technical Notes page. Page last reviewed:June 10,2020 https://www.cdc.gov/nchs/nvss/vsrr/covid_weeklylndex.htm 4/4 6/15/2020 COVID-19 Provisional Counts-Weekly Updates by Select Demographic and Geographic Characteristics !q Select Sex Select Measure Reporting Period All sex vCOVID-19 Deaths v Week ending 2/1/2020 through 6/6/2020 Provisional Death Counts,by Week Ending Date and Age Group Age Group 00-24 years 025-34 years 035-44 years 045-54 years 055-64 years 065-74 years 75-84 years 085 years and over SIC 41K 31K 21K 01K �gl'l "01 1�0 01 "01 N01 "01 �O 01 o", 01 619 41 Week ending Date NOTE:Provisional death counts are based on death certificate data received and coded by the National Center for Health Statistics as of the date of analysis and do not represent all deaths that occurred in that period. SOURCE:NCHS,National Vital Statistics System.Estimates are based on provisional data. Microsoft Power BI < 1 of 2 > Race and Hispanic origin Table 2a compares the percent distribution of deaths involving coronavirus disease 2019(COVID-1 9)with weighted distributions of COVID-1 9 deaths to population by race and Hispanic origin group',for the United States and jurisdictions with more than 100 deaths available for analysis.Table 2b includes the percent distributions of the unweighted United States population by race and Hispanic origin.To download the data, pClick hereto download. Table 2c has death counts for COVID-1 9 by race and Hispanic origin group by age group for the United States. For data on race and Hispanic origin by age at the state level, Click hereto download. Place of death Table 3 presents death counts of COVID-1 9 and other select causes of death by the place of death. For data on place of death at the state level, I - I-. I . 0 ® . 8 _. - I * 9 1 , 9 - Isom . am M a . It a-. -1 . - __ - 0 . 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