Pandemic-related measures lead to decline in other respiratory illnesses
Other respiratory viral infections, including influenza, have declined significantly at a Connecticut hospital during the COVID-19 pandemic, according to a study published in Open Forum Infectious Diseases.
Researchers attributed the decline to the widespread use of public health interventions to slow the pandemic.
“We have tracked respiratory viral infections for many years and noticed a profound difference this year as COVID-19 appeared and the state began to enforce various public health measures, including the promotion of wearing a face mask, better hand hygiene, social distancing, and stay-at-home policies,” Michael Parry, MD, Thomas J. Bradsell chair of infectious diseases at Stamford Health and professor of clinical medicine at Columbia University Vagelos College of Physicians and Surgeons, told Healio.
Research has shown that efforts to prevent COVID-19 have led to a global decline in influenza. For their study, Parry and colleagues analyzed the incidence of all viral respiratory illnesses diagnosed at Stamford Hospital in the last 5 years during a 16-week period from April through July.
According to the study, these weeks coincided with high COVID-19 activity and increased use of masks, social distancing and hand hygiene. The researchers divided the study into two periods: a 4-year period from 2016 to 2019, referred to as the “historical seasons” and the 2020 season.
The study demonstrated that during the historical seasons, the Stamford Hospital laboratory diagnosed a total of 327 influenza cases and 223 positive BioFire cases (used for diagnosing all other respiratory infections) for an average 138 combined cases per season, whereas only one case of influenza and three Biofire cases were diagnosed during the same period in 2020.
The study also demonstrated that positive Biofire and influenza tests were significantly lower during the 2020 season. Only 1.4% of Biofire tests were positive in the 2020 season compared with 38.9% in the historical seasons (P < .00001) despite the increased volume of testing performed in 2020 (212 tests in 2020 compared with an average of 141 in the historical seasons), whereas only 1.3% of influenza tests were positive in 2020 compared with 10.8% of tests performed during the historical seasons.
The researchers noted that fewer influenza/respiratory syncytial virus tests were performed in 2020 compared with historical seasons (76 compared with an average of 754).
“We think that the systematic use of masking, hand hygiene, social distancing and stay-at-home policies can dramatically reduce the risk of all viral respiratory tract infections, including influenza,” Parry said. “If an individual wants to maximize their protection from colds and flu, these interventions — plus influenza vaccination — will definitely help.”