Hepatitis B viral markers in Bushmen at Schmidtsdrift, South Africa: baseline studies for immunisation.

In an effort to control hepatitis B virus (HBV), the prevalence rates of the virus need to be ascertained in different regions or populations. As a baseline for a hepatitis B immunisation programme, the seroprevalence of HBV markers was determined in 400 San Bushmen from a community who were translocated from Northern Namibia to South Africa. HBsAg was detected in 6.8% while 57.0% showed one or more markers of HBV infection. The balance of the population (43.0%) showed no evidence of previous exposure to HBV. The HBV exposure rate of 57.0% is intermediate to high with reference to internationally reported figures and protection of seronegative individuals through immunisation is recommended. Individuals without possible natural immunity against HBV such as those with anti-HBc or anti-HBs as a sole marker may provide insight into the circulation of HBV mutants in this community, since these sole markers could be seroconversion in response to a mutant HBV strain.