Public health officials continue to urge us all to use face masks, physical distancing and hand washing to reduce the spread of COVID-19. But many individuals seem unconvinced that such efforts are helpful. They point to a lack of scientific evidence on the value of face masks. Two new studies bolster that evidence substantially.
Global Research on the Value of Face Masks:
A study published in BMJ Global Health (May 28, 2020) suggests that measures such as washing hands, maintaining distance and wearing face masks do indeed reduce the risk of spreading or catching the coronavirus. Researchers tracked 335 people in 124 families in which one person tested positive for SARS-CoV-2. The goal of the study was to determine how many people in the families caught the virus and if there were any strategies that worked to prevent secondary infection within two weeks of contact.
Almost one fourth of the other family members became infected after contact with one ill member. The risk of transmitting the infection was highest before symptoms developed or early in the disease. This makes isolation or distance much more difficult to use effectively. However, when people in the family wore face masks, washed their hands, disinfected surfaces and used good ventilation, they reduced viral transmission. When people were wearing face masks in the home as a preventive measure before the first family member got ill, other family members were 79 percent less likely to catch the virus. This certainly highlights the value of face masks.
If the initial patient had diarrhea, family members were four times more likely to get sick as well. However, disinfecting the bathroom and closing the toilet lid before flushing were helpful. These could be helpful tactics even after the pandemic has finished.
Another Study on Covering the Face:
A second study published recently confirms the value of face masks. This meta-analysis of 172 studies found that wearing face masks and using eye protection can reduce the risk of contracting COVID-19 (The Lancet, June 1, 2020). Maintaining physical distance between infected and uninfected people was also critical.
Canadian investigators reviewed data collected from more than 25,000 volunteers in 16 countries. The researchers analyzed infection rates of coronaviruses including SARS, MERS and SARS-CoV-2. They found that maintaining at least three feet of distance was better than close contact. The farther away people were from each other, the lower the risk of viral transmission.
In addition, people who used face masks conscientiously were less likely to transmit the infection.
The investigators state that
“Face mask use could result in a large reduction in risk of infection, with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar [reusable 12-16-layer cotton masks]. Eye protection also was associated with less infection.”
The evidence that N95 respirators provide much stronger protection means that all health care workers and other essential employees should have access to such protective gear. So should anyone who is at high risk for catching SARS-CoV-2. Moreover, in high-risk settings such as hospitals, goggles or face shields offer an extra layer of protection to bolster the value of face masks.