Absence of HTLV-III/LAV antibodies in ex-residents from Angola and Mozambique returning to Portugal before 1979.

We analyzed the prevalence of antibodies to HTLV-III/LAV in ex-residents from Angola and Mozambi que who returned to Portugal (Lisbon) before 1979. The absence of antibodies to HTLV-III/LAV suggests that the infection was not highly prevalent in these African countries before the development of the AIDS epidemic in the United States. Further studies of this type in ex-residents from other areas of Africa may be of help in the analysis of the difficult question of whether HTLV-III LAV originated in the African continent.