An out-break of acute gastroenteritis due to rotavirus in an infant home.

In December 1976, an outbreak of acute infectious diarrhea occurred among infants who resided in an infant home in the city of Sapporo. Rotavirus infection was proved in 42 (90%) of 47 infants by serologic and/or electron microscopic examinations. Out of 42 infected infants 38(90%) were clinically affected; diarrhea with or without vomiting in 27 (64%), vomiting without diarrhea in 6 (14%) and only febrile episode in 5 (12%). The remaining 4(10%) infants showed no symptoms. Clinical manifestations seemed to differ depending on age. Diarrhea without vomiting was more common in the patients younger than 6 months of age, and vomiting or fever was more common in the groups of older age. Possible reasons for such an age dependency were discussed on the basis of complement-fixation tests using human and calf strains of rotavirus.