Spread and distribution of human T-cell leukaemia virus type I-reactive antibody among baboons and monkeys in the northern and eastern Transvaal.

Antibodies which probably indicate infection with human T-cell leukaemia virus type I (HTLV-I) were determined in three species of non-human primates from several localities. A significant prevalence among chacma baboons and vervet monkeys was confirmed. According to sero-epidemiological evidence that HTLV-I infection is predominantly sexually transmitted between adult animals; comparison of prevalence rates between localities or species should therefore take sexual maturity into account. It appears unlikely that transmission from non-human primates to humans is frequent.