Respiratory syncytial virus shedding by children hospitalized with lower respiratory tract infection.

Children with respiratory syncytial virus (RSV) infection shed virus for variable periods. The aim of this study was to quantify the viral load in nasopharyngeal aspirates of children with RSV throughout their hospitalization. This study included 37 children who were admitted with a diagnosis of RSV infection based on a positive rapid diagnostic test. Nasopharyngeal aspirates were collected from patients every day, from admission to discharge. Viral detection and quantification were performed using quantitative real-time PCR. Of the 37 patients, RSV-A was detected in 29 and RSV-B in 6. Two patients were PCR-negative for any type of RSV. RSV-A was detected in 12 of 16 patients (75%) 6 days after admission. These patients shed detectable virus from days 1 to 12, and for a significantly longer period (mean 5.7 days) than RSV-B (mean 3.8 days) patients. Half of the RSV-A patients were also positive on day 14 following onset. RSV-A was detected in patients <12 months of age for significantly longer periods after onset than in patients ≥12 months of age. RSV-A viral load was negatively correlated with days from admission and days from onset. Because RSV shedding was frequently prolonged, the hospitalized children may have contracted RSV as a nosocomial infection. To prevent nosocomial RSV infections in hospital wards, healthcare workers must take appropriate infection control measures and provide adequate guidance on hand washing to the family of the patient.