The prevalence of markers of infection with hepatitis B virus in a mixed-race Australian community.

A seroepidemiological study of markers of infection with hepatitis B virus was conducted in Brewarrina, a mixed-race township in north-western New South Wales. Six hundred and forty-three subjects, who represented 41.5% of the town's population, were screened for a range of serological markers of hepatitis B virus infection. Of the Aboriginal subjects, 72% had markers which indicated previous infection with hepatitis B virus, with 19.2% of subjects being identified as hepatitis B surface antigen (HBsAg)-seropositive. In the non-Aboriginal subjects, the prevalence of infection with markers of hepatitis B virus was 13.1%, with 2.2% of subjects being HBsAg-seropositive. The marker prevalences for Aboriginal and non-Aboriginal subjects in the 15- to 19-year-old age-group were 86.7% and 28%, respectively. The prevalence of hepatitis B virus infection in the total non-Aboriginal sample was higher than it is in the general Australian blood-donor population. The extent to which hepatitis B virus infection may result from cross-infection between coexisting "high-risk" and "low-risk" population groups is speculative. Furthermore, the risk of infection to non-Aborigines is unlikely to be spread evenly across the non-Aboriginal community. The cost of vaccine remains high, and until further data become available, mass vaccination of the population probably is not warranted. Initially, control measures should concentrate on the reduction of hepatitis B virus infection in the Aboriginal population and in non-Aboriginal households which contain a HBsAg-seropositive member.