TOPLINE: 

In outpatient care, children younger than 2 years who tested positive for respiratory syncytial virus (RSV) infection had higher rates of wheezing, crackles, and tachypnoea and experienced greater disease severity. Having preschool-aged siblings and atopic eczema each independently increased the risk for RSV infection.

METHODOLOGY:

• This prospective study in Germany assessed the prevalence, clinical features, risk factors, comorbidities, and treatment outcomes of RSV infection in children younger than 2 years.
• A total of 1450 children (median age, 12 months; 50.6% boys) with at least one symptom of lower respiratory tract infection were enrolled at five outpatient primary care centres between October 2021 and April 2023.
• Nasopharyngeal swabs were tested using multiplex polymerase chain reaction for RSV A/B and other respiratory viruses; children were classified as testing positive or negative for RSV.
• Children testing positive for RSV had a routine follow-up visit on day 14 and another visit on day 28 if symptoms persisted to record symptom duration, complications, treatments, and healthcare use.
• Disease severity was graded with the Paediatric Respiratory Severity Score, used to evaluate respiratory rate, wheezing, use of accessory muscles, feeding difficulty, and general appearance.

TAKEAWAY:

• RSV was detected in 19.7% of children, making it the second most common pathogen after rhinovirus/enterovirus, with clear seasonal peaks.
• Children testing positive for RSV had higher rates of wheezing, crackles, and tachypnoea as well as moderate-to-severe disease than those testing negative (P < .001 for all comparisons).
• In adjusted analysis, having a preschool-aged sibling (odds ratio [OR], 1.65; P = .001) and atopic eczema (OR, 1.65; P = .031) independently predicted RSV infection; food allergy was also more common in children who tested positive for RSV (P = .02).
• Among children testing positive for RSV, the most frequently used medications were inhaled short‑acting beta‑agonists, inhaled saline, and antipyretics; the mean time to symptom resolution was 12 days.

IN PRACTICE:

"Our prospectively collected data provide valuable baseline information prior to the widespread implementation of novel RSV preventive interventions and will contribute meaningfully to the evaluation and refinement of RSV prevention strategies both within Germany and internationally," the authors wrote. 

SOURCE:

The study was led by Alexander Kiefer, University Children's Hospital Regensburg at the Hospital St. Hedwig of the Order of St. John, University of Regensburg, Germany. It was published online on March 01, 2026, in the International Journal of Infectious Diseases.

LIMITATIONS: 

The study lacked systematic follow-up visits for children testing negative for RSV, limiting direct comparisons of outcomes and treatments. Participating centres represented only a portion of paediatric primary care in Germany, limiting the generalisability of the findings. Because enrolment began each autumn to coincide with typical RSV activity, extraseasonal cases in 2021 may have been missed.

DISCLOSURES:

The study was funded by Sanofi and AstraZeneca. One author disclosed receiving consultation and lecture fees from Sanofi, AstraZeneca, MSD, and Pfizer.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.