The prevalence of serological markers for hepatitis B virus infection in Australian Naval personnel.

In order to determine the prevalence of hepatitis B virus infection in Royal Australian Navy personnel and to formulate policies for their education, screening and vaccination, a voluntary survey was undertaken. Seven hundred and forty-eight subjects completed a questionnaire that provided details of age, sex, rank, ethnic origin, service abroad, length of service, history of tattooing, liver disease and blood transfusions. Serum was assayed by radioimmunoassay for the presence of hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (antiHBs) and antibody to hepatitis B core antigen (antiHBc). The presence of markers of hepatitis B virus infection was correlated with "risk factors" by means of the chi 2 test of independence. Fourteen (74%) of 19 personnel from the Pacific Islands, Asia and Africa who were excluded from analysis showed one-or-more such markers. The prevalence of any marker of hepatitis B virus infection was 4.4% (95% confidence interval [CI], 2.9%-5.9%). The individual markers HBsAg, antiHBs and antiHBc were found in 0.4% (95% CI, 0.1%-1.2%), 3.6% (95% CI, 2.2%-4.9%) and 3.9% (95% CI, 2.5%-5.3%) of subjects, respectively. The annual attack rate was estimated to be less than 1%. Factors which had a significant correlation with an increased prevalence of markers of hepatitis B virus infection included tattooing (especially if this had been performed in Asia), age, the duration of service and service abroad. Based on these data, and given the reduced cost of hepatitis B vaccines, vaccination now is considered worth while. A policy of vaccinating all personnel who may be required for service at sea, and others at risk, now is in effect. Educational programmes that are aimed at minimizing the risk of exposure to hepatitis B and other viral infections have been instituted.