Prevention of RSV infection in infancy could reduce childhood asthma cases by 15%.

Bronchiolitis caused by respiratory syncytial virus (RSV) in infancy is associated with later childhood asthma, but it is not clear whether less-severe RSV disease in infancy also increases asthma risk. To clarify this issue, researchers recruited 2000 healthy full-term babies in central Tennessee and contacted parents every two weeks during each child’s first RSV season. Nasal washes from children with acute respiratory infections were tested for RSV by polymerase chain reaction, and disease severity was assessed. All children had RSV serum antibody titres at age 1 year and were followed for five years for asthma symptoms, diagnosis or treatment.

At age 1 year, 54% of children had evidence of RSV infection. Compared with children who had RSV as infants, those who were not infected had a 26% lower risk for current asthma at age 5 years. Children with more-severe RSV infection during infancy had a higher risk for current asthma at age 5, and most of the excess asthma among children infected with RSV as infants was non-atopic.

Comment: These findings suggest that any RSV infection in infancy – not just RSV bronchiolitis – is associated with later childhood asthma. The authors estimate that 15% of asthma cases at age 5 could be prevented by population interventions that prevent, delay or decrease the severity of RSV infection in infancy.

Bruce Soloway, MD, Associate Professor Emeritus of Family and Social Medicine, Albert Einstein College of Medicine, Bronx, New York, USA.

Rosas-Salazar C, et al. Respiratory syncytial virus infection during infancy and asthma during childhood in the USA (INSPIRE): a population-based, prospective birth cohort study. Lancet 2023 Apr 19; e-pub (https://doi.org/10.1016/S0140-6736(23)00811-5).

This summary is taken from the following Journal Watch titles: Infectious Diseases, Pediatrics and Adolescent Medicine.