BACKGROUND: In western countries, the transmission of human herpesvirus 8 (HHV-8) via blood transfusion has been recently postulated. In sub-Saharan African, the incidence of HHV-8-associated Kaposi's sarcoma and the seroprevalence for HHV-8 in autochthonous populations are high. STUDY DESIGN AND METHODS: The aim of this study was to estimate the prevalence of blood donations potentially infectious for HHV-8 in the general adult population of Central Africa. Forty-nine blood donors at the Centre de Transfusion Sanguine in Bangui, the capital of the Central African Republic, were selected. Forty-five inpatients of Broussais Hospital, Paris, France, who were known to be seronegative for HIV and hepatitis B and C viruses and who had not received heart or kidney transplants, were chosen as a European "control" group for comparison. HHV-8 DNA sequences were detected in peripheral blood mononuclear cells by nested polymerase chain reaction using primer sets located in the HHV-8 open reading frame 26. RESULTS: Eleven (22.5%; 95% CI: 12%-37%) of 49 blood donors were positive for HHV-8. Three (6%) were HIV-1 seropositive. Two (67%) of the 3 HIV-infected blood donors were also positive for HHV-8. All blood donors were apparently healthy; none was known to suffer from Kaposi's sarcoma. Only one (2.2%) control was carrying HHV-8 DNA on the peripheral blood mononuclear cells. The prevalence of HHV-8 was higher in blood donors from Bangui than in patients from Broussais Hospital. CONCLUSIONS: HHV-8 infection is highly prevalent in an apparently healthy adult population from Central Africa, which raises concerns about HHV-8 transmission through transfusion in this setting.