HIV-1, HIV-2, HTLV-I/II and Treponema pallidum infections: incidence, prevalence, and HIV-2-associated mortality in an occupational cohort in Guinea-Bissau.

Infection with HIV-2 is strongly linked geographically to West Africa where it was first detected in 1985-86. In that region the highest seroprevalence of HIV-2 is found in Guinea-Bissau where HIV-1 infection has previously been rare. The authors assessed the prevalence and incidence of HIV-1 HIV-2 HTLV I/II and syphilitic infections and the association between these infections in a cohort of 1241 male and 143 female police officers in Guinea-Bissau between January 1990 and December 1992. The overall seroprevalence of HIV-1 was 0.4%; HIV-2 11.6%; and HTLV I/II 4.4%. 0.2% were seropositive for both HIV-1 and HIV-2. Women had a significantly higher prevalence of HIV-2 infection than men: 16.8% and 11.0% respectively. Serologic evidence of previous syphilis was found in 12.1% of subjects and was significantly more common among men than women: 12.7% and 7.0% respectively. A significant association was found between the prevalence of HIV-2 and HTLV I/II infection. The annual incidence of HIV-1 was 0.7% 1.6% for HIV-2 0.4% for HTLV I/II and 1.7% for syphilis with no association found between the incidence of various infections. The death rate was 2.7% among HIV-2-infected individuals compared to 0.5% among HIV-negative individuals. The disproportionately high incidence of HIV-1 infection relative to its low prevalence indicates a recent increase in the spread of HIV infection in the country.