HTLV-I AMONG NORTHERN-TERRITORY ABORIGINES

Objective: To survey the Aboriginal community of the Northern Territor y for antibodies to human T-lymphotropic virus type I (HTLV-I) and to describe the distribution of the virus. Design: A sero-epidemiological study using the Serodia particle-agglutination assay, indirect immuno fluorescence and western blot. Evidence of HTLV-I-related diseases was sought through clinicians, and by searching the cancer register and m edical records. Sera: Samples from 1897 Aborigines, including 1569 ser a received by the Royal Darwin Hospital Pathology Department for syphi lis serology between March and July 1988. Most of the specimens were f rom public health surveys and antenatal screening. Results: Ninety-fou r samples (5.0%) were positive by the particle-agglutination assay met hod but only 36 (1.9%) were positive by both particle-agglutination as say and indirect immunofluorescence. After confirmation by western blo t, the seroprevalence of HTLV-I was 1.7% (95% confidence interval, 1.2 -2.3%). Western blot positivity was higher in samples from the ''Cattl e Country'' and Alice Springs regions (i.e., 4.7% and 13.9% respective ly). Conclusion: HTLV-I is endemic among Aborigines in inland Australi a. These serological findings are supported by the recognition of two cases of adult T-cell leukaemia/lymphoma in this population.