Low prevalence of community-acquired influenza coinfections among COVID-19 patients in Al-Madinah, Saudi Arabia: A retrospective cohort study.

Background: Coinfections with respiratory viruses among SARS CoV-2 patients have been reported by several studies during the current COVID-19 pandemic. Most of these studies designated these coinfections as being hospital-acquired infections; however, there is inadequate knowledge about community-acquired respiratory coinfections among SARS CoV-2 patients.

Methods: In this retrospective cohort study, we investigated the seroprevalence of influenza A, influenza B, and parainfluenza-2 among newly hospitalized patients with confirmed COVID-19 infections (n = 163). The study was conducted during the early phase of the COVID-19 pandemic in Saudi Arabia (from April to October 2020). The patients' serum samples were subjected to commercial immunoglobulin M (IgM) antibody tests against the three aforementioned viruses.

Results: Seropositivity for influenza A and B and parainfluenza-2 occurred only in 4.2% (7/163) of COVID-19 patients, indicating simultaneous acute infections of these three viruses with SARS CoV-2 infection. All coinfection cases were mild and misdiagnosed during the care period in the hospital.

Conclusion: This study highlights the low prevalence of community-acquired respiratory infections among COVID-19 patients in the current pandemic and we discussed the possible factors for this finding. During newly emerging epidemics or pandemics, considering other respiratory viruses circulating in the community is essential to avoid their misdiagnosis and account for their possible negative effects on pandemic disease management and prognosis.