Food-borne Outbreak of Gastroenteritis Caused by Small Round Structured Virus

In December 1989, an outbreak of gastroenteritis associated with cake consumption occurred in a day-care center with 60 children and 12 staff in Saitama prefecture. Children were served cakes at the Christmas party held in the day-care center and ate them with their families. Thirty-three of the 59 children (56%), 16 of the 74 families (22%) and 1 of the 10 staff (10%) eating the cakes became ill. Illness consisted primarily of nausea, vomiting, diarrhea and fever; the median incubation period was 31 hours. Bacteriological analysis of stool specimens did not reveal a causative agent. Small round structured viruses (SRSV) were detected in fecal specimens from 10 of the 17 ill children (59%) and 2 of the 6 ill families (33%) by electron microscopy. Cakes were purchased from a bakery where an employee who prepared the cake denied symptoms, and SRSV was not detected in the fecal specimen from the employee. Thus, it was not determined that the cake was contaminated by a food handler.