Respiratory syncytial virus infection in infants in rural Nepal

OBJECTIVES: Respiratory syncytial virus (RSV) pneumonia is a leading cause of infant mortality worldwide. The risk of RSV infection associated with preterm birth is not well-characterized in resource-limited settings. We aimed to obtain precise estimates of risk factors and disease burden of RSV in infants in rural southern Nepal. METHODS: Pregnant women were enrolled, and along with their infants, followed to six months after birth with active weekly home-based surveillance for acute respiratory illness (ARI). Mid-nasal swabs were obtained and tested for RSV by PCR for all illness episodes. Birth outcomes were assessed at a postpartum home visit. RESULTS: 311 (9%) of 3509 infants had an RSV ARI. RSV ARI incidence decreased from 551/1000 person-years in infants born between 28 and 31 weeks to 195/1000 person-years in infants born full-term (p = 0.017). Of 220 infants (71%) evaluated in the health system, 41 (19%) visited a hospital or physician. Of 287 infants with an assessment performed, 203 (71%) had a lower respiratory tract infection. CONCLUSIONS: In a rural south Asian setting with intensive home-based surveillance, RSV caused a significant burden of respiratory illness. Preterm infants had the highest incidence of RSV ARI, and should be considered a priority group for RSV preventive interventions in resource-limited settings.