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 infection in rural Australian Aboriginal populations in the ''Top End'' of the Northern Territory. Methods: A total of 344 sera, for which details of donors' age, sex and domicile were available, were collected and 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 104/105 (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. Symptomatic hepatitis A infection is uncommon in this population. We suggest that hepatitis A vaccination for rural Aboriginal children is not indicated as it would not reduce clinical disease rates and may produce a cohort whose immunity could decrease over the following 10 years. Although vaccination is appropriate for non-immune individuals working in remote communities, emphasis must be placed on the inequities in health infrastructure and education underlying the high transmission rates in Aboriginal children.