Mandatory in certain global regions to limit the spread of covid-19, face masks could be here to stay, even after the pandemic subsides. In fact, new research from the US indicates that face masks, together with other covid-19 precautions, may have led to a dramatic decrease in rates of common respiratory viral infections, such as colds and flu.
A team of researchers from Boston Medical Center (BMC) have investigated the impact of the precautions used to halt the pandemic on common respiratory illnesses, other than covid-19. To do so, they performed a retrospective cohort analysis of all the respiratory viral infections documented (among inpatients and outpatients) at BMC at certain periods between January 1, 2015, and November 25, 2020. Positive and negative results for SARS-CoV-2 tests were excluded from the study to focus on other common respiratory illnesses.
The scientists explain that 2020 was divided into two specific periods -- the first preceding mask wearing, social distancing and school closures, and the second spanning the weeks and months during which these practices became the norm. "We know viruses that cause the common cold and pneumonia are spread through close contact, aerosols and/or droplets, which is why we decided to look into how the measures implemented to prevent the spread of covid-19 may have impacted the incidence of other common viral respiratory illnesses," said Manish Sagar, MD, an infectious diseases physician and researcher at BMC and the study's corresponding author.
An 80% reduction in respiratory viral infections
The study findings, published online , showed an approximately 80% reduction in cases of influenza and other common respiratory viral infections when compared to similar time periods in previous years -- before mask wearing, social distancing and school closures were implemented to help stop the spread of covid-19. This figure suggests that these precautions, initially implemented to combat covid-19, could prove useful in the future to prevent other respiratory viral infections.
During 2020, the scientists noted that there were more respiratory viral infections in the first period -- before the implementation of restrictions and precautions -- compared to 2015 to 2019. Similarly, Boston's phased re-opening in July 2020 was associated with an increase in the detection of rhinovirus infections.
"Our study results may be particularly helpful for developing prevention strategies in settings where respiratory infections are very harmful, such as congregate settings and for the elderly and immunosuppressed," concludes Manish Sagar.