COVID-19 Study Reveals Sex Differences in Influenza A and Higher ICU Incidence of Human Metapneumovirus

Strategic Insights -

A new study published in BMC Infectious Diseases has shed light on the epidemiology and sex differences of community respiratory viruses, including human metapneumovirus (HMPV), in the pre-COVID-19 era. The research, conducted at UMass Memorial Medical Center between January 2010 and December 2013, examined the characteristics of 4,098 patients who tested positive for at least one respiratory virus. The study found that 75.3% of individuals testing positive were inpatients, with rhinovirus/enterovirus being the most frequently detected virus. Interestingly, the study revealed a higher incidence of influenza A infections among women and a higher ICU incidence of HMPV in the elderly population.

Key Takeaways:

  • The study examined the epidemiology and sex differences of community respiratory viruses, including HMPV, in 4,098 patients at UMass Memorial Medical Center between January 2010 and December 2013.
  • The majority (75.3%) of individuals testing positive for at least one virus were inpatients.
  • Rhinovirus/enterovirus was the most frequently detected virus, accounting for 26.6% of all positive tests.
  • Influenza A infections were more common in older adults, with 23.4% of all positive tests being due to this virus.
  • RSV incidence was highest among patients 65 years of age or older, with 14.1% of all positive tests due to this virus.
  • The study found a higher incidence of HMPV in the ICU among the elderly, underscoring the importance of testing in this population.
  • The study confirms known epidemiology, seasonality, and coinfections, but also reveals a preponderance of influenza A infections among women and a higher ICU incidence of HMPV in the elderly.

Statistics:

  • 4,098 patients tested positive for at least one respiratory virus.
  • 75.3% of individuals testing positive were inpatients.
  • Rhinovirus/enterovirus was detected in 26.6% of all positive tests.
  • Influenza A infections accounted for 23.4% of all positive tests.
  • RSV incidence was highest among patients 65 years of age or older, at 14.1% of all positive tests.
  • The study found a higher ICU incidence of HMPV in the elderly, at 6.3% of all positive tests.

Sources:

  • BMC Infectious Diseases, 2025;25(1)
  • Medical Letter on the CDC & FDA, August 17, 2025; p 323
  • Bibek Koirala, UMass Chan Med Sch, Dept. of Medicine, Division of Infectious Diseases and Immunology, 55 Lake Ave North, S7-835, Worcester, MA 01655, United States
  • Additional authors: Richard T. Ellison III, Aline Azar, Brianna Fountain, Melissa McGuirl, Shannon Stock, and Marzena Galdzicka.