Sporadic norovirus infections among hospitalized and non-hospitalized 0-3-year-old infants.

Little is known of the frequency of norovirus infections in sporadic gastroenteritis cases. In a 4-y study, we examined 1152 rota-, adeno- and astrovirus negative stool samples for human noroviruses; 187 (16.2%) proved to be positive. Stool samples were from paediatric patients with acute gastroenteritis. All isolates were verified as sporadic cases: there was no accumulation.