In a recent study published on the preprint server medRxiv, researchers from the United States evaluated the effectiveness of face masks in an epidemic of SARS-CoV-2, severe acute respiratory syndrome.

In public places, face masks play an important role in preventing the spread of coronavirus 2019 (COVID-19). Their wearing was recommended by the World Health Organization in June 2020, but there is still no scientific evidence regarding the epidemiological effectiveness against the transmission of the virus.

Teaching

The research team conducted a thorough review of relevant studies published between April and August 2020, excluding those presented at conferences.

PRISMA criteria were used – preferred reporting elements for systematic reviews and meta-analyses. Three team members identified 1,732 articles.

Of them, 61 articles met the criteria. Finally, the study evaluated 13 articles. The team evaluated relative risk, frequency, statistical tests, and confidence intervals to calculate variation between groups who reported using or not wearing face masks in the community and health care settings.

result

A total of 1,539 subjects from 13 studies were analyzed, of which four were in the community and nine were in health care settings. Of them, 243 were infected with the coronavirus, 97 wore and 146 did not wear masks.

The team noted that the chance of becoming infected was 7% for those wearing masks and 52% for those not wearing masks.

The relative risk was 0.13 for those wearing a mask.

In medical institutions, 9% of carriers and 33% of non-carriers became ill, corresponding to a relative risk of 0.20 for carriers. And in the community, the team noted that 6% of carriers and 83% of non-carriers tested positive for SARS-CoV-2.

The community relative risk was 0.08 for mask wearers.

The results showed a link between mask use and positive tests, as 92% of mask wearers did not test positive for Covid-19. The relationship between positive attitudes and mask use varied significantly between health facilities and communities.

In total, 50% of those who did not wear masks did not get Covid-19. It is noteworthy that 83% of people who did not wear masks in the community contracted the disease, compared to 33% in medical facilities.

Overall, the study found that people who wear masks are less likely to contract the disease in health care facilities and communities. As new information becomes available, further research will be required. The researchers believe that future studies are needed to determine the impact of the rules on the use of masks and other measures to prevent the transmission of Covid-19.

Source: Medical News