HealthDay News — Wearing face masks could be slightly protective against primary infection with influenza-like illness from casual community contact, according to a review that has not yet been peer reviewed and was posted online April 6 at medRxiv.org.
Julii Brainard, Ph.D., from Norwich Medical School at the University of East Anglia in the United Kingdom, and colleagues reviewed 31 eligible studies, including 12 randomized controlled trials (RCTs), relating to development of respiratory illness to examine the value of wearing face masks.
The researchers found that most studies reported on the use of medical-grade surgical paper masks. Wearing a face mask was associated with a very slight reduction in the odds of developing influenza-like illness/respiratory symptoms in three RCTs (odds ratio, 0.94; 95 percent confidence interval, 0.75 to 1.19). Observational studies suggested greater effectiveness. The odds of further household members becoming ill were modestly reduced when both housemates and an infected household member wore face masks (odds ratio, 0.81; 95 percent confidence interval, 0.48 to 1.37). A very small protective effect was seen if only the well person (odds ratio, 0.93; 95 percent confidence interval, 0.68 to 1.28) or the infected person (odds ratio, 0.95; 95 percent confidence interval, 0.53 to 1.72) wore a face mask.
“Although we can support vulnerable people who choose to wear masks to avoid infection, we want to remind everyone that the people who most need to wear masks, to protect us all, are health care workers,” Brainard said in a statement. “We are all in more danger from COVID-19 if health care workers cannot obtain the safety equipment they need, which could happen if community demand for face masks becomes too high.”