Wednesday, July 15, 2020

The Case For Universal Masking : CDC, MMWR & JAMA

How to Wear Face Cover















#15,354

Six months into this COVID pandemic and science is finally catching up to what many people have known instinctively for years (or decades) to be true; that wearing a mask or face cover during a pandemic is a pretty good idea.

Getting here hasn't been easy. People in Western countries have been so indoctrinated against wearing masks, that getting them to do it now (and properly) hasn't been easy. 

As a result, many Asian countries - where mask wearing is promoted and socially acceptable - are having a much easier time controlling the COVID-19 pandemic. Over the last six months Taiwan, remarkably, has had only 451 cases while Hong Kong is just shy of 1,600 cases, South Korea has less than 15,000, and Japan is just over 22,000. 

Their combined 6 month total is considerably less than what the United States reported over just  the past 24 hours (n=65,000).

And while the there are many factors involved, the biggest difference has been the near universal use of masks and face coverings in Asia during this pandemic - and during every flu season for many years -  while their use was officially discouraged here until April 2020 (see EID Journal (Letter): On The Wearing Of Face Masks In Public).

Someday scholars much smarter than I will look back and try to figure out how this scientific blind spot remained `conventional wisdom' until roughly 3 months ago.  

But for now, the important thing is that universal masking by the public is probably the only thing we can do today that is likely to substantially reduce the number of new coronarvirus infections. Today we've an editorial and a study in JAMA, an early release from the MMWR, and a plea from the CDC on the importance of mask wearing during this pandemic. 

First stop, from the JAMA NETWORK:

Editorial
July 14, 2020
Universal Masking to Prevent SARS-CoV-2 Transmission—The Time Is Now

Author Affiliations Article Information
JAMA. Published online July 14, 2020. doi:10.1001/jama.2020.13107

(EXCERPT)

In this issue of JAMA, Wang et al present evidence that universal masking of health care workers (HCWs) and patients can help reduce transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections.1 In the largest health care system in Massachusetts with more than 75 000 employees, in tandem with routine symptom screening and diagnostic testing of symptomatic HCWs for SARS-CoV-2 infection, leadership mandated a policy of universal masking for all HCWs as well as for all patients.
 
The authors present data that prior to implementation of universal masking in late March 2020, new infections among HCWs with direct or indirect patient contact were increasing exponentially, from 0% to 21.3% (a mean increase of 1.16% per day). However, after the universal masking policy was in place, the proportion of symptomatic HCWs with positive test results steadily declined, from 14.7% to 11.5% (a mean decrease of 0.49% per day). Although not a randomized clinical trial, this study provides critically important data to emphasize that masking helps prevent transmission of SARS-CoV-2.
 

The aforementioned study can be read at:
Association Between Universal Masking in a Health Care System and SARS-CoV-2 Positivity Among Health Care Workers
Xiaowen Wang, MD1; Enrico G. Ferro, MD2; Guohai Zhou, PhD3; et alDean Hashimoto, MD, JD4; Deepak L. Bhatt, MD, MPH1
Author Affiliations Article Information
JAMA. Published online July 14, 2020. doi:10.1001/jama.2020.12897

Next stop, and early release from the CDC's MMWR.

Early Release / July 14, 2020 / 69

M. Joshua Hendrix, MD1; Charles Walde, MD2; Kendra Findley, MS3; Robin Trotman, DO4 (View author affiliations)




 








Summary
What is already known about this topic?

Consistent and correct use of cloth face coverings is recommended to reduce the spread of SARS-CoV-2.

What is added by this report?

Among 139 clients exposed to two symptomatic hair stylists with confirmed COVID-19 while both the stylists and the clients wore face masks, no symptomatic secondary cases were reported; among 67 clients tested for SARS-CoV-2, all test results were negative. Adherence to the community’s and company’s face-covering policy likely mitigated spread of SARS-CoV-2.

What are the implications for public health practice?

As stay-at-home orders are lifted, professional and social interactions in the community will present more opportunities for spread of SARS-CoV-2. Broader implementation of face covering policies could mitigate the spread of infection in the general population.
         (SNIP)
The results of this study can be used to inform public health policy during the COVID-19 pandemic. A policy mandating the use of face coverings was likely a contributing factor in preventing transmission of SARS-CoV-2 during the close-contact interactions between stylists and clients in salon A. Consistent and correct use of face coverings, when appropriate, is an important tool for minimizing spread of SARS-CoV-2 from presymptomatic, asymptomatic, and symptomatic persons. CDC recommends workplace policies regarding use of face coverings for employees and clients in addition to daily monitoring of signs and symptoms of employees, procedures for screening employees who arrive with or develop symptoms at work, and posted messages to inform and educate employees and clients (https://www.cdc.gov/coronavirus/2019-ncov/community/organizations/businesses-employers.html).

(Continue . . . )

These studies add incrementally to what we've known for months, and in many cases, for years.  Masks and face covers - while not perfect - work to reduce disease transmission during a respiratory disease outbreak.  

Bur if we hope to put a dent into this pandemic wave, we need to use them religiously, and properly, whenever we leave our homes.  And from what I've seen the past few weeks where I live (central Florida), we have a ways to go.

In view of these latest studies, the CDC released the following media release yesterday.


JAMA editorial reviews latest science, while case study shows masks prevented COVID spread
Press Release

For Immediate Release: Tuesday, July 14, 2020
Contact: Media Relations
(404) 639-3286

Americans are increasingly adopting the use of cloth face masks to slow the spread of COVID-19, and the latest science may convince even more to do so.

In an editorial published today in the Journal of the American Medical Association (JAMA), CDC reviewed the latest science and affirms that cloth face coverings are a critical tool in the fight against COVID-19 that could reduce the spread of the disease, particularly when used universally within communities. There is increasing evidence that cloth face coverings help prevent people who have COVID-19 from spreading the virus to others.

“We are not defenseless against COVID-19,” said CDC Director Dr. Robert R. Redfield. “Cloth face coverings are one of the most powerful weapons we have to slow and stop the spread of the virus – particularly when used universally within a community setting. All Americans have a responsibility to protect themselves, their families, and their communities.”

This review included two case studies out today, one from JAMA, showing that adherence to universal masking policies reduced SARS-CoV-2 transmission within a Boston hospital system, and one from CDC’s Morbidity and Mortality Weekly Report (MMWR), showing that wearing a mask prevented the spread of infection from two hair stylists to their customers in Missouri.

Additional data in today’s MMWR showed that immediately after the White House Coronavirus Task Force and CDC advised Americans to wear cloth face coverings when leaving home, the proportion of U.S. adults who chose to do so increased, with 3 in 4 reporting they had adopted the recommendation in a national internet survey.

The results of the Missouri case study provide further evidence on the benefits of wearing a cloth face covering. The investigation focused on two hair stylists — infected with and having symptoms of COVID-19 — whose salon policy followed a local ordinance requiring cloth face coverings for all employees and patrons. The investigators found that none of the stylists’ 139 clients or secondary contacts became ill, and all 67 clients who volunteered to be tested showed no sign of infection.

The finding adds to a growing body of evidence that cloth face coverings provide source control – that is, they help prevent the person wearing the mask from spreading COVID-19 to others. The main protection individuals gain from masking occurs when others in their communities also wear face coverings.

COVID-19 prevention in a Missouri hair salon

When two stylists at a Missouri hair salon tested positive for the virus that causes COVID-19, researchers from CoxHealth hospitals, Washington University, the University of Kansas, and the Springfield-Greene County Health Department worked together to trace contacts, investigate the cases, and publish their findings in the MMWR.

One of the stylists developed respiratory symptoms but continued to see clients for eight days. The other, who apparently became infected from her co-worker, also developed respiratory symptoms and continued to see clients for four days.

The salon in which they worked had a policy requiring both stylists and their clients to wear face coverings, consistent with the local government ordinance. Both stylists wore double-layered cloth face coverings or surgical masks when seeing clients. The median appointment time was 15 minutes and ranged from 15 to 45 minutes. More than 98% of clients wore a face covering—47% wore cloth face coverings, 46% wore surgical masks, and about 5% wore N-95 respirators.

When customers were asked whether they had been ill with any respiratory symptoms in the 90 days preceding their appointment, 87 (84%) reported that they had not. None of the interviewed customers developed symptoms of illness. Among 67 (48%) customers who volunteered to be tested, all 67 tested negative for the virus that causes COVID-19. Several family members of one of the stylist’s subsequently developed symptoms and received a diagnosis of COVID-19.

Survey: Acceptance of face-mask guidance increased

CDC analyzed data from an internet survey of a national sample of 503 adults during April 7–9 and found that about 62% said they would follow the newly announced recommendations to wear a face mask when outside the home. A repeat survey during May 11-13 showed that the percentage of adults endorsing face mask wearing increased to more than 76%.

The increase was driven largely by a significant jump in approval by white, non-Hispanic adults, from 54% to 75%. Approval among Black, non-Hispanic adults went up from 74% to 82%, and remained stable among Hispanic/Latino adults at 76% and 77%.

There was also a large increase in face-mask approval among respondents in the Midwest, from 44% to 74%. Approval was greatest in the Northeast, going from 77% to 87%.

Resources:
CDC Editorial in JAMA: Brooks JT, Butler JC, Redfield RR. Time for universal masking and prevention of transmission of SARS-CoV-2. JAMA. Published online July 14, 2020. doi:10.1001/jama.2020.13107 https://jamanetwork.com/journals/jama/fullarticle/10.1001/jama.2020.13107
MMWR Article: No Transmission of Symptomatic SARS-CoV-2 After Significant Exposure With Universal Face Mask Use at a Hair Salon – Springfield, Missouri, May 2020 https://www.cdc.gov/mmwr/volumes/69/wr/mm6928e2.htm?s_cid=mm6928e2_w
MMWR Article: Factors Associated with Cloth Face Coverings Use during the COVID-19 Pandemic — United States, April and May 2020 https://www.cdc.gov/mmwr/volumes/69/wr/mm6928e3.htm?s_cid=mm6928e3_w 



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