SHOULD ABORIGINALS IN THE TOP END OF THE NORTHERN-TERRITORY BE VACCINATED AGAINST HEPATITIS-A

Objective: To determine the level of immunity to hepatitis A virus inf ection in rural Australian Aboriginal populations in the ''Top End'' o f the Northern Territory. Methods: A total of 344 sera, for which deta ils of donors' age, sex and domicile were available, were collected an d tested for hepatitis A total antibody in a delinked sero-prevalence study. Results: Overall, 337/344 samples (97.97%) tested positive for hepatitis A total antibodies - 18/20 samples (90%) in the 1-5 year age group; 85/88 (96.6%) in the 6-10 year age group; 98/98 (100%) in the 11-15 year age group; 32/33 (97.0%) in the 16-20 year age group and 10 4/105 (99%) in the older than 20 year age group. Conclusion: Hepatitis A is hyperendemic in the rural Aboriginal communities studied and the virus is acquired predominantly in the first five years of life. Symp tomatic hepatitis A infection is uncommon in this population. We sugge st that hepatitis A vaccination for rural Aboriginal children is not i ndicated as it would not reduce clinical disease rates and may produce a cohort whose immunity could decrease over the following 10 years. A lthough vaccination is appropriate for non-immune individuals working in remote communities, emphasis must be placed on the inequities in he alth infrastructure and education underlying the high transmission rat es in Aboriginal children.