The following is a summary of “Clinical features and outcomes of influenza and RSV coinfections: a report from Canadian immunization research network serious outcomes surveillance network,” published in the January 2024 issue of Infectious Diseases by Pott et al.

While infrequent, concurrent infections of influenza and RSV pose significant concerns due to their potential to precipitate severe illness and unfavorable clinical consequences, particularly in susceptible demographics.

Researchers conducted a retrospective study to delineate the clinical characteristics and assess outcomes associated with coinfections of influenza and RSV among hospitalized adults.

They used combined active surveillance data from hospitalized adults aged 50 and older, drawn from the Serious Outcomes Surveillance Network of the Canadian Immunization Research Network (CIRN SOS) during the influenza seasons ( 2012/13, 2013/14, and 2014/15). Descriptive statistics were employed to outline the features of influenza/RSV coinfections, while Kaplan-Meier analysis estimated survival probabilities during the initial 30 days of hospitalization.

The result showed that over 3 influenza seasons, 33 instances of RSV and influenza coinfection were identified, representing a frequency of 2.39 cases per 1,000 hospitalizations among patients with acute respiratory illnesses. For adults aged 50 years and older, commonly reported symptoms included cough (81.8%), shortness of breath (66.7%), sputum production (45.5%), weakness (33.3%), fever (27.3%), and nasal congestion (24.2%). The mortality rate was notable at 12.1%, with age, comorbidity burden, and frailty demonstrating associations with elevated risks for adverse clinical outcomes.

Investigators concluded that adults over 65 with multiple health conditions face a heightened risk of severe complications from combined influenza and RSV infections.

Source: bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-024-09033-5