Potential spectrum of etiological agents of viral enteritis in hospitalized infants.

Fecal specimens were obtained from 1,160 infants and young children with acute nonbacterial gastroenteritis over a period of 2 years. A total of 100 specimens were obtained from age-matched asymptomatic controls. The specimens were examined for the presence of viruses by electron microscopy. Viruses or virus-like particles frequently associated with enteritis were detected in 27% (314 of 1,160) of the symptomatic patients. No viruses or virus-like particles were detected in the 100 control subjects. Rotavirus was detected in 73% (230 of 314) of the virus-positive samples. The mean age of rotavirus-positive patients was 11.5 months, although the patients ranged in age from 2 weeks to 5 years. Of the symptomatic patients, 45 (14%) exhibited small virus-like particles (15 to 40 nm) in the feces in the absence of any other detectable pathogen. Some of the virus-like particles observed in these patients appeared to be similar to astrovirus, and some appeared to be similar to the Otofuke agent or possibly minireovirus. Significantly, however, the mean age of infants with enteritis from whom these small virus-like particles were recovered was 4.5 months (range, 10 days to 19 months). Our findings confirmed the already-known fact that rotaviruses constitute the most important cause of viral enteritis in young children. In addition, small viruses may be an important cause of gastroenteritis in infants under 5 months of age.