The shield and mask is a winning combination, says Ahmed Hakki, a physician from New York, in a letter to The New York Times editor for the Opinion column published earlier in August. “Front-line workers in emergency rooms wear a face shield on top of a mask. This protects their eyes from getting infected by coronavirus droplets and provides added protection if their mask is ill-fitting. My wife and I wear an N95 or KN95 mask and a face shield whenever we leave our apartment,” advises Dr. Hakki. “Clearly, teachers should do so if schools reopen,” he adds.
In the NEJM Journal Watch article editor-in-chief David G. Fairchild, MD, MPH, focuses on the research published on the JAMA’s website in August. “Wearing a face shield on top of a surgical mask may reduce community health workers’ risk for COVID-19. After face shields were added, no workers tested positive.”
It’s also worth mentioning that in the separate article on JAMA, Eli Perencevich, M.D., published in July, a professor of internal medicine and epidemiology at the University of Iowa Carver College of Medicine, and two of his colleagues pointed to such benefits of shields for infection prevention. They are referring to a study published back in 2014. “Face shields appear to significantly reduce the amount of inhalation exposure to influenza virus, another droplet-spread respiratory virus. In a simulation study, face shields were shown to reduce immediate viral exposure by 96 percent when worn by a simulated health care worker within 18 inches of a cough.” JAMA Network is the Journal of the American Medical Association peered-reviewed medical journal that publishes research, reviews, and editorials on all aspects of biomedicine. ”Biggest benefit of face shields would be inside crowded office situations where air exchanges aren’t ideal,” added Dr. Eli Perencevich.
On August 11, there is original investigation research again published on JAMA about the Filtration Efficiency of Hospital Face Mask Alternatives Available for Use During the COVID-19 Pandemic. A Controlled Air Purifying Respirator system that was tested in a particular study fitted with a face shield supplied by the device manufacturer prevented more than 99% of particles from entering the test individual’s breathing space.