HTLV-III antibody positivity in Zambian copper belt [letter]

Studies in Lusaka have shown that an aggressive form of Kaposis sarcoma (KS) in Zambia is linked to infection by the AIDS virus (HTLV-III/LAV). Several patients with lymphadenopathy syndrome (LAS) were also seen and they too were seropositive. Sera taken at the same time from healthy people in the Lusaka area indicated that the virus was not endemic. Many of the patients presenting with KS or LAS had lived in or had associations with the copper belt which lies to the north of Lusaka adjacent to the border with Zaire. We have looked at the HTLV-III antibody status in the normal population living in the Zambian copper belt. Sera were collected over a period of 3 months and stored before despatch to the UK for testing for antibodies to HTLV-III/LAV by a competitive enzyme-linked immunosorbent assay (ELISA). In contrast with our findings in Lusaka HTLV-III appears to be endemic in the copper belt of Zambia. Both training school students and the Zambian Consolidated Copper Mines staff regarded themselves as healthy. The samples taken at random at the Konkola Mine Hospital were from patients presenting with a variety of diseases and complaints not obviously associated with AIDS. The virus does not seem to have infected a population of prisoners who are physically separated from the natural community; however only 24 such sera have been tested. The results of this small survey are at variance with our previous findings in Zambia. This may be due to a rapid increase in the background prevalence of the AIDS virus in the normal population or more likely to sampling error associated with patchy distribution of the virus in a recently infected community. (full text)