RSV-Bacterial Co-Infection Is Associated With Increased Illness Severity in Hospitalized Children - Results From a...

Area of Science:

• Pediatric Infectious Diseases
• Respiratory Medicine
• Epidemiology

Background:

• Bacterial co-infections are common during respiratory syncytial virus (RSV) epidemics, influencing disease severity.
• Changes in RSV seasonality post-COVID-19 pandemic warrant re-evaluation of co-infection impacts.

Purpose of the Study:

• To investigate the relationship between RSV-bacterial co-infections and clinical severity in hospitalized children.
• To assess the impact of co-infections on hospitalization length and disease severity following pandemic-related seasonality shifts.

Main Methods:

• Prospective, sentinel surveillance study conducted across 20 sites in Portugal.
• Involved 678 children under 2 years hospitalized with RSV between April 2021 and January 2023.
• Multivariate regression models analyzed the effect of potentially pathogenic bacteria (PPB) co-infection on hospitalization length and severity.

Main Results:

• 20.4% of RSV hospitalizations involved co-infection with potentially pathogenic bacteria (PPB).
• Children with PPB co-infection had higher ICU admission rates (29.7% vs. 3.5%) and prolonged hospitalizations (7 vs. 5 days).
• RSV-bacterial co-infection was associated with a 13-fold increased risk of severe disease (RR: 13.2).

Conclusions:

• RSV-bacterial co-infection significantly increases hospitalization length and disease severity, even during off-season epidemics.
• The observed risk may be overestimated due to biased laboratory testing in severely ill children.
• Discussing preventive measures against pathogenic bacterial outgrowth in the respiratory tract is recommended.