June 2020 COVID-19 News
TL; DR: Wear your mask, any mask that covers your nose and mouth but read the fine print. (see caveats below). Visit with friends and family outdoors.
The Take Home:
The safest way to spend time with others is outside, 6 feet apart from each other, with everyone wearing a mask.
The Background:
Covid 19 spreads among persons in close proximity through droplets, and possibly through airborne transmission. The use of respiratory personal protective equipment (PPE) may decrease the risk for respiratory infections but which type of mask to use and when a mask is necessary is controversial. No direct evidence exists for the effectiveness or comparative effectiveness of various masks in the community. Low-certainty indirect evidence found that mask use may reduce the risk of Covid-19 versus no mask in the community. The WHO notes potential risks associated with mask use, including self-contamination (via improper handling of masks), breathing difficulties, and a false sense of security.
The Support:
The Department of Health in Minneapolis set up 4 sites for testing after the recent protests in the city. 3,200 people were tested and of those only 1.8% were positive for Covid-19. Health Partners, a large health care provider in Minnesota reported to the state that it tested 8,500 people who indicated that attendance at a mass gathering was the reason they wanted a test. Among them, 0.99% tested positive. These rates of positivity are similar to the expected background transmission rate. Dr. Roger Shapiro, a professor of immunology and infectious diseases at Harvard thinks this low transmission rate is due to protesters wearing masks and being outdoors. Linsey Marr, a professor of environmental engineering at Virginia Tech, thinks the low transmission rates are in large part due to the outdoor environment of the protests due to the dilution of the virus particles.
The Caveats:
The Annals of Internal Medicine article provides useful information of the proper use of a mask. Following these recommendations should make the mask more effective:
1. Persons should clean their hands with soap and water or alcohol-based rub before putting on a mask.
2. Masks should be properly fitted and should cover the mouth and nose, with no gaps between face and mask. All masks should be extended under the chin.
3. Persons should avoid touching the mask and their face, and should especially avoid touching their face when wearing a mask, as well as putting it on and taking it off.
4. When taking a mask off, it should be removed from behind without ever touching the front of the mask.
5. Once the mask is removed, hands again should be cleaned with soap and water or alcohol based rub.
The References:
1. Amir Quaseem, Md, PhD, MHA, Itziar Etxeandia-Ikobaltzeta, PharmD, PhD et al. “Use of N95, Surgical, and Cloth Masks to Prevent Covid-19 in Health Care and Community Settings: Living Practice Points From the American College of Physicians (Version 1)”. Annals of Internal Medicine Special Articles 18 June, 2020. https://doi.org/10.7326/M20-3234.
2. Holteni, Megan. “What Minnesota’s Protests Are Revealing About Covid-19 Spread”. Wired Magazine, 16 June, 2020. https://www.wired.com/story/what-minnesotas-protests-are-revealing-about-covid-19-spread/
Author: Alice L. Fuisz, M.D., M.A.C.P.
