COVID-19 Precautions Also Decreased Rates of Common Respiratory Illnesses

Common precautions used to prevent the spread of COVID-19—such as mask wearing and physical distancing—also decreased the rates of common respiratory illnesses in 2020 and early 2021, according to new research published in Open Forum Infectious Diseases.

Researchers at Boston Medical Center (BMC) showed an approximately 80% reduction in cases of influenza and other common viral respiratory infections compared to similar time periods in previous years, when wearing masks, physical distancing, and school closures were not widely implemented. The results suggest that public health measures used to prevent COVID-19 transmission could also be useful in preventing other respiratory viral infections, according to the study authors.

“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 corresponding author Manish Sagar, MD, an infectious diseases physician and researcher at BMC, in a press release.

The investigative team performed a retrospective cohort analysis to analyze all documented respiratory viral infections at BMC for time periods between January 1, 2015, and November 25, 2020. These infections were diagnosed using a comprehensive respiratory panel polymerase chain-reaction test, which the study authors said scans for 20 common respiratory pathogens. Positive and negative results for SARS-CoV-2 tests were excluded given the focus on other common respiratory illnesses prior to the COVID-19 pandemic.

According to the study, the year 2020 was divided into 2 periods: before the implementation of mask wearing, physical distancing, and school closures (called period 1), and after the implementation of these practices (period 2). The researchers analyzed the number of viral infections during periods 1 and 2 for 2015 through 2019 and compared it to the 2020 results.

In period 2 of 2020, after the implementation of measures to stop COVID-19, newly detected respiratory viruses were approximately 80% lower compared to the same time period from 2015 to 2019. On the other hand, in period 1 of 2020, there were more respiratory virus infections compared to 2015 through 2019. Furthermore, the researchers noted that the phased re-opening in Boston, which began around July 20, 2020, was associated with an increase in the detection of rhinovirus infections.

The findings could help experts develop prevention strategies for future cold and flu seasons, even after the COVID-19 pandemic, according to the study authors.

“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,” Sagar explained in the press release.

REFERENCE

Study: Precautions Used to Prevent COVID-19 Decreased Common Respiratory Illness Rates [news release]. EurekAlert; March 23, 2021. https://www.eurekalert.org/pub_releases/2021-03/bmc-spu032321.php. Accessed April 1, 2021.