Tuberculosis surveillance in the South Australian aboriginal community

Tuberculosis (TB) is still a significant problem in Aboriginal people. There are higher rates of active TB and evidence of continuing transmission among this group. We sought to define the specific epidemiological risks and best methods of surveillance for TB in Aboriginal people in South Australia. We compared the incidence of active TB in Aboriginal people in South Australia with that of the total number of cases in non-Aboriginal people from 1978 to 1988, and studied the prevalence of infection in four Aboriginal communities in South Australia. Incidence rates of active TB were four times higher in South Australian Aboriginal people than the total South Australian rates. Specific age analysis revealed higher active disease notification rates in Aboriginal people aged 45-54 years and 55-64 years. The notification rate for Aboriginal men was almost three times the rate for women. Standardized incidence ratios of active TB cases for Aboriginal communities were higher in rural and traditional communities than in urban Aboriginal people. Infection prevalence, measured by tuberculin skin testing, varied from 7.7% to 30.8% in the different communities but did not correlate with the standardized incidence ratios. We conclude that (i) South Australian Aboriginal people are suffering a higher rate of active TB disease than the total South Australian community, and (ii) that the disease and infection rates vary between communities and between age and sex groups. The discrepancy between disease notifications rates, as measured by standardized incidence ratios, and infection prevalence requires further investigation. To improve TB control in Aboriginal people, programmes need to be altered to be more appropriate for this group.