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The Centers for Disease Control and Prevention emphasized in its latest scientific briefing released on Tuesday that wearing a mask can protect the wearer, not just others from the coronavirus. The agency stated that the more people wear masks consistently and correctly, the stronger the protective effect of masks.
When the CDC first advised Americans to wear cloth face masks in April, it cited evidence that the coronavirus may be transmitted by asymptomatic people, who may not know their infectiousness, which is estimated to account for 50% of the transmission. the above. The agency said the purpose of masks is to prevent infected persons from distributing virus particles.
In the report updated Tuesday, the CDC said that this is still the main purpose of wearing a mask. However, it also cited more and more evidence that even cloth masks can reduce the amount of infectious droplets inhaled by the wearer.
“This message is the key to increasing compliance and interest in wearing masks. I am very happy!” Dr. Monica Gandhi, an infectious disease physician at the University of California, San Francisco, said in a tweet on Tuesday.
In a recently published study, Ghandi pointed out that even if a person wearing a mask is infected, wearing a mask can reduce the severity of COVID-19.
As for which mask to choose? The CDC pointed out that as far as cloth masks are concerned, layers with a higher thread count are better for protecting the wearer than a single-layer cloth with a lower thread count.
Dr. Scott Segal, professor and chair of anesthesiology at Wake Forest School of Medicine, has been testing various masks since March. He shared a rule of thumb with NPR earlier this year: place the fabric in bright light or in the sun. He said that if you can “see the light outlines the contours of the individual fibers in the fabric, it may not be a good filter. If you can’t see it, it may filter better.”
(If you want more advice on choosing masks, please refer to our guide.)
In its new scientific brief, the CDC reviews the epidemiological and observational evidence on the use of masks and the spread of coronavirus. This included a study of 124 families in Beijing, at least one of whom had a laboratory-confirmed case of COVID-19. As we have already reported, when everyone in the family wears a mask as a preventive measure before the infected person starts to show symptoms, the risk of transmission is reduced by 79%.
Another study highlighted by the Centers for Disease Control and Prevention found that among 1,000 contacts in Thailand, those who were reported to wear masks during the high-risk exposure period had a 70% lower risk of infection compared with those who did not. % Above these situations.
The CDC also pointed to a study that found that when masks are strictly worn on long-distance flights, infected passengers will not spread the virus to anyone else on the plane.
The CDC points out that, in addition, “seven studies have confirmed the benefits of universal shielding technology in community-level analysis.” This includes research on masks in hospital systems, German cities, and multiple states in the United States, and across the United States and Canada.
The CDC writes: “Each analysis shows that according to the organization and political leadership’s instructions on universal screening, new infections have dropped significantly.” The CDC said that two of the studies and other analyses indicate widespread cover-ups. The policy reduced the mortality rate.
Interestingly, the CDC’s scientific briefing also cited the economic argument of masks and pointed out an analysis using US data, which found that “increasing general-purpose masks by 15% can prevent the need for lock-in and reduce up to $1 trillion or About 5% of the related loss. GDP.”