Hepatitis A in day-care centers. A community-wide assessment.

We investigated the spread of viral hepatitis in day-care centers in Maricopa County, Ariz. Over a 10-month period, 398 (40 per cent) of 1008 reported cases of hepatitis Type A or viral hepatitis of unspecified type occurred in persons closely associated with day-care centers. Outbreaks of hepatitis comprising 310 cases were identified in 30 of 308 centers in the county. In 28 outbreaks investigated, the majority of symptomatic cases occurred in household contacts or close relatives of children who attended day-care centers, with 16 per cent of the cases occurring in children who attended the centers and 15 per cent occurring in employees. Hepatitis in both employees and household contacts was strongly related to contact with children one to two years of age who attended the centers (P less than 0.001). Day-care centers appear to be important in the spread of hepatitis A in the United States.