Pre-COVID-19 epidemiology of community respiratory viruses at a single US center reveals sex differences in influenza A and a higher ICU incidence of human metapneumovirus in the elderly population.

Abstract

Background: Few studies have simultaneously examined the epidemiology and sex differences of diverse community respiratory viruses, including human metapneumovirus (HMPV), over more than one season.

Methods: Given that molecular testing for community respiratory viruses was widely performed on patients at UMass Memorial Medical Center between January 2010 and December 2013, a retrospective study was conducted to examine epidemiologic features of positive subjects. Initial testing was done with rapid influenza and respiratory syncytial (RSV) virus antigen testing, with negative testing reflexed to a multiplex nucleic acid amplification platform detecting nine respiratory viruses.

Results: Four thousand ninety-eight (50.6%) of 8092 patients tested positive for at least one virus. The majority (75.3%) of individuals testing positive were inpatients. Rhinovirus/enterovirus was most frequently detected; influenza A was more common in older adults and RSV incidence was highest among patients < 5 years of age. Pronounced seasonality was seen with influenza viruses, RSV, HMPV, and parainfluenza 3 virus. Influenza A was significantly more common in females (11.2% vs. 8.1%; p < 0.001), while parainfluenza 1 virus (2.0% vs. 1.2%; p < 0.01), rhinovirus/enterovirus (23.4% vs. 19.9%; p < 0.001) and adenovirus (2.1% vs. 1.5%; p < 0.05) were significantly higher in males. Of the ICU patients with HMPV, many (40.3%) were ≥ 65 years of age.

Conclusions: This pre-coronavirus disease 2019 (COVID-19) era study has one of the largest patient populations evaluated for community respiratory virus infections. It confirms known epidemiology, seasonality, and coinfections, and importantly shows a preponderance of influenza A infections among women, contrasting prior studies, which warrants further investigation. It also shows a high HMPV incidence in the ICU among the elderly, underscoring the importance of testing in this population.