Hepatitis B virus transmission between children in day care.

We investigated two situations involving hepatitis B virus exposure among children in day care. In the first a 4-year-old boy who attended a day care center developed acute hepatitis B; another child at the center, who had a history of aggressive behavior (biting/scratching), was subsequently found to be a hepatitis B carrier. No other source of infection among family and other contacts was identified and no other persons at the center became infected. In the second situation a 4-year-old boy with frequently bleeding eczematous lesions was discovered to be a hepatitis B carrier after having attended a day care center for 17 months. Testing of contacts at the center revealed no transmission to other children or staff (representing 887 person months of exposure). Nationwide surveillance data showed that for the period 1983 to 1987, 161 children 1 to 4 years of age were reported with acute hepatitis B. After children with known hepatitis B risk factors were excluded, 25% (7 of 28) of children with known day care status were reported as day care attendees, a percentage comparable to national estimates of day care attendance by this age group. This is the first reported case of hepatitis B virus transmission between children in day care in the United States. Although it appears that day care transmission of hepatitis B is infrequent, further studies are needed to define the risk more accurately.