Sixty-eight lorry drivers and their assistants were examined for evidence of infection with HIV-1 because of their association and regular contact with prostitutes. Out of a total of 68 drivers, 24 (35.2%) were serologically found to be HIV-1 positive. Epidemiological evidence demonstrated a wide travel history involving seven different countries served by the port of Mombasa. History of other sexually transmitted disorders were significantly higher in HIV-seropositive individuals. The data presented here further support the hypothesis that a major route of heterosexual transmission of HIV in Africa is dissemination through a group such as lorry drivers and their assistants, whose behaviour puts them at risk of acquiring sexually transmitted diseases.
PIP: Participants in the study were drivers and turnboys who passed through a transport depot in Kampala, Uganda, in November 1986. Each participant answered a questionnaire aimed at determining basic demographic data, countries visited within the previous 3 years, level of prostitute contact within those countries, and whether they had had a history of urethral discharge or genital ulceration. A total of 45 drivers and 23 turnboys with a mean age of 38 and 26 years, respectively, were interviewed and blood samples were taken. Serological controls were selected from people of the same age as the study group from individuals donating blood. Serum immunoglobulin (Ig) antibodies to HIV were determined by a competitive enzyme-linked immunosorbent assay and a competitive ELISA using recombinant HIV core and envelope proteins. All serological results were verified by immunoblot assays or were prepared by electrophoretic separation of U937 cell lysates infected with a Ugandan HIV-1 isolate. Antibodies to Treponema pallidum were detected by a hemagglutination test. They were of Ugandan (66.2%) or Kenyan (33.8% ) origin. All were sexually active, and all denied homosexuality and intravenous drug use. The overall HIV-1 seropositivity rate was 35.2%, compared with the control group of 9.2% (24 out of 68 versus 12 out of 130; p 0.01). Using the antigen detection systems, 7 of the seronegative sera proved to be antigen positive. In addition, 4 out of the 24 seropositive sera (16.6%) also proved to be antigen positive. 36.7% of the population admitted more than 50 lifetime sexual partners. Of the remainder, 83.7% had had more than 10 lifetime sexual partners. The level of urethral discharge and genital ulceration revealed a significant difference (p 0.01) between seropositive and seronegative individuals. The overall level (55.8%) of T. pallidum antibodies among drivers and turnboys was significantly higher than in the control group (p 0.01). The drivers had the highest level of T. pallidum antibodies (62.2%) compared with turnboys (43.8%), reflecting the older average age and, thus, the greater sexual experience.