Clinical viral hepatitis B among Minnesota hospital personnel. Results of a ten-year statewide survey.

We report a ten-year survey of clinical hepatitis B virus (HBV) infections in Minnesota hospital personnel. Between 1974 and 1983, a total of 561 personnel cases of viral hepatitis were identified. Four hundred twelve cases were diagnosed as type B, with 399 cases (97%) identified as work related. Of the 177 hospitals in the state, only 42 (24%) reported cases during the ten-year period. The highest annual incidence of type B cases was in 1975 (127/100,000 personnel) and decreased to the lowest incidence in 1983 (8/100,000 personnel). The incidence for personnel at hospitals with long-term hemodialysis decreased from 418/100,000 personnel in 1975 to 16/100,000 personnel in 1983, while the incidence for employees in hospitals without hemodialysis decreased from 16 to 5/100,000 personnel for the same time. The decrease in the incidence of hepatitis B in personnel occurred before the use of HBV vaccine. Our findings indicate that HBV seroprevalence studies significantly overestimate the current incidence of HBV infections among personnel in most hospital settings.