Respiratory viral co‐infections in patients with COVID‐19 and associated outcomes: A systematic review and meta‐analysis

The aim of this systematic review and meta‐analysis was to critically assess the published literature related to community‐acquired viral co‐infections and COVID‐19 and to evaluate the prevalence, most identified co‐pathogens, and relevant risk factors. Furthermore, we aimed to examine the clinical features and outcomes of co‐infected compared to mono‐infected COVID‐19 patients. We systematically searched PubMed, Web of Science, Embase, Scopus, and The Cochrane Library for studies published from 1 November 2019 to 13 August 2021. We included patients of all ages and any COVID‐19 severity who were screened for respiratory viral co‐infection within 48 h of COVID‐19 diagnosis. The main outcome was the proportion of patients with a respiratory viral co‐infection. The systematic review was registered to PROSPERO (CRD42021272235). Out of 6053 initially retrieved studies, 59 studies with a total of 16,643 SARS‐CoV‐2 positive patients were included. The global pooled prevalence was 5.01% (95% CI 3.34%–7.27%; I ( 2 ) = 95%) based on a random‐effects model, with Influenza Viruses (1.54%) and Enteroviruses (1.32%) being the most prevalent pathogens. Subgroup analyses showed that co‐infection was significantly higher in paediatric (9.39%) than adult (3.51%) patients (p‐value = 0.02). Furthermore, co‐infected patients were more likely to be dyspnoeic and the odds of fatality (OR = 1.66) were increased. Although a relatively low proportion of COVID‐19 patients have a respiratory viral co‐infection, our findings show that multiplex viral panel testing may be advisable in patients with compatible symptoms. Indeed, respiratory virus co‐infections may be associated with adverse clinical outcomes and therefore have therapeutic and prognostic implications.