Risk factors for severe respiratory syncytial virus infection among Alaska Native children

Objective. The incidence of hospitalization for respiratory syncytial virus (RSV) infection among Alaska Native children is much higher than among non-Native populations in the United States. We conducted this study to better understand factors associated with hospitalization attributable to RSV infection in this high-risk population. Design. Case-control study, including collection of cord blood for RSV-neutralizing antibody measurement. Setting. Remote region of southwest Alaska served by 1 regional hospital and 2 referral hospitals. Subjects. Case-patients identified through surveillance for RSV infection and matched control subjects without acute respiratory infection hospitalization. Results. Breastfeeding was associated with a lower risk of RSV hospitalization (odds ratio: 0.34), whereas underlying medical conditions (primarily prematurity) were associated with increased risk (odds ratio: 6.25). Environmental factors associated with a higher risk of hospitalization included household crowding (4 or more children in the household and crowding index ≥2). The level of maternal RSV-neutralizing antibody was not associated with the risk of hospitalization. Conclusions. In this region with extremely high risk of RSV hospitalization, several measures, such as encouraging breastfeeding and reducing household crowding, could reduce the risk of hospitalization attributable to RSV.