Risk factors for HIV/AIDS in a low HIV prevalence site of sub-Saharan Africa.

We conducted a hospital-based survey on prevalence and risk factors of HIV-1/2 and other viral infections in Zanzibar archipelago. Blood samples, socio-demographic and behavioural data were collected from 2697 patients. The overall HIV prevalence was 2.9%. About 1.4%, 2.1%, 4.2% of antenatal clinic (ANC) attendees and 2.1%, 3.7%, 5.3% of blood donors were, respectively, HIV-Abs-, HTLV-Abs- and HBs-Ag-positive; 5.5% of blood donors were HCV-affected. Co-infections were rare. Exactly 3.4% of the children aged 6-10 years were HIV-positive. People aged 26-35 years [adjusted odds ratio (AOR) 4.4, 95% CI (confidence interval) 1.72-11.22; P = 0.002], illiterate subjects (AOR 3.6, 95% CI 1.65-7.98; P = 0.001) mobile workers (AOR 7.0, 95% CI 1.41-34.62; P = 0.02) and previously operated patients (AOR 1.9, 95% CI 1.02-3.66; P = 0.04) were at higher risk for HIV/AIDS. Any of the examined factors were associated with hepatitis B virus, hepatitis C virus and human T lymphotropic virus type 1/2 transmission. HIV/AIDS prevention strategies must primarily be addressed to traditional high-risk groups and secondarily to unsafe health care procedures in relatively preserved sub-Saharan areas.