REGIONAL DIFFERENCES IN HUMAN RETROVIRAL INFECTIONS HIV-1, HIV-2, AND HTLV-I/II IN RURAL GUINEA (WEST AFRICA)

The authors performed a seroepidemiological survey of retroviral infections in three geographically and ethnically diverse rural areas of Guinea with the purpose of assessing and evaluating variations in the prevalence of HIV-1 HIV-2 and HTLV-I. The survey was conducted over six weeks in January and February 1992 in Samoe in the Forest Guinea Boulivel in the center of Middle Guinea and Koumbia in north Middle Guinea. 2285 individuals aged 2-97 years were surveyed: 928 in Samoe 543 in Boulivel and 814 in Koumbia. The participation rate was approximately 80% in Samoe and Koumbia but 30% in Boulivel due to their lack of understanding of the aims of the study. The study was therefore extended in the schools. Mean ages of the participants ranged 22.1-24.3 years. The prevalence of HIV infection was 1.3% in Koumbia and 0.7% in Samoe in the over 20 age group. HIV infection was found in neither Boulivel nor among participants younger than 20 years old. In Koumbia only HIV-2 infection was detected. In Samoe two men were infected with HIV-1 and one woman was coinfected with HIV-1 and HIV-2; they were not however relatives. Rates of HTLV-I infection were 0.5% 0.7% and 1.9% in Koumbia Boulivel and Samoe respectively with prevalence increasing significantly with age and being higher among women than among men. No evidence was found of infection with HTLV-II. Three cases of interspousal transmission and two cases of perinatal transmission were identified. These findings seem to point to the existence of a general spatial expansion of HIV infection linked to trucking routes and trucker migrations including seasonal labor migrations. Still low levels of HIV prevalence in Guinea however suggest that a concerted HIV prevention effort could avert an epidemic.