Human astrovirus-associated gastroenteritis in children under 2 years of age followed prospectively during a rotavirus vaccine trial

This study evaluated the clinical significance of human astrovirus-associat ed gastroenteritis in young children in the community. Placebo- (n = 1207) and rhesus rotavirus tetravalent (RRV-TV) vaccine- (n = 1191) recipient chi ldren were followed from 2 mo to 2 y of age. Stool specimens from 1528 epis odes of acute gastroenteritis (805 in the placebo group and 723 in the RRV- TV vaccine group) were tested for astrovirus with a sensitive reverse trans cription-polymerase chain reaction (RT-PCR) assay and positive results were confirmed by Southern hybridization using probes specific for astrovirus s erotypes 1 and 2. Astroviruses were detected in 144 (9%) episodes of gastro enteritis; 92% of the findings were serotype 1 and 6% were serotype 2. The astrovirus peak season was in winter. Of the 102 children who had gastroent eritis with astrovirus as the only diarrhoea virus in the stools, 72% had w atery diarrhoea, 59% had vomiting, 26% had fever, 5% needed oral rehydratio n and 3% were hospitalized. Overall, the clinical severity of astrovirus ga stroenteritis was much lower than that of rotavirus gastroenteritis. RRV-TV rotavirus vaccine did not protect against astrovirus gastroenteritis. It i s concluded that astroviruses are common causative agents in acute gastroen teritis in young children, but the symptoms of astrovirus gastroenteritis a re usually mild and the illness is therefore only of minor clinical signifi cance.