Neonates at greatest risk of RSV hospitalization

It turns out that infants who are about 1 month of age are at greatest risk of being hospitalized because of a respiratory syncytial virus (RSV) infection.

Although experts have known that RSV is a leading cause of hospitalization among infants, it has been unclear at exactly which age infants are at greatest risk.

Researchers analyzed data from a 5-year, prospective, population-based study of young children hospitalized with laboratory-confirmed RSV acute respiratory illness (ARI) between 2000 and 2005.

Approximately one-quarter (26%) of the more than 2,000 children in the study were hospitalized with an ARI caused by RSV. The researchers discovered that infants aged 1 month had the highest rate of RSV hospitalization at 25.9 per 1,000 children, followed by infants aged less than or equal to 2 months with a rate of 17.9 per 1,000, and finally by those aged younger than 1 month with a rate of 13.5 per 1,000 children. Combined, infants aged 2 months and younger represented almost half (44%) of all the RSV hospitalizations in the study.

Only about 36% of hospitalizations occurred in infants aged older than 5 months. The average RSV hospitalization rate for all children aged younger than 2 years over the 5-year period was 5.2 per 1,000 children.

Very-preterm infants (less than 30 weeks’ gestation) accounted for only 3% of RSV cases, but had hospitalization rates 3 times those of full-term infants.

Because most (79%) of the RSV-hospitalized children were previously healthy, the investigators emphasized that general preventive strategies are required for all children, not just for those with risk factors, in order to reduce RSV hospitalizations.

According to the Centers for Disease Control and Prevention, almost all children will be infected with RSV by their second birthdays. 

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