Evidence of stable HIV seroprevalences in selected populations in the Democratic Republic of the Congo.

OBJECTIVE To determine current data on HIV infection and to document changes and trends of HIV seroprevalence in selected populations over time in the Democratic Republic of the Congo (DRC; former Zaïre). METHODS In February 1997, a large serosurvey was conducted on selected population groups from Kinshasa (capital city), Mbuji-May (southeast) and Bwamanda (northwest). Samples obtained from pregnant women, tuberculosis patients, commercial sex workers, blood donors and sexually transmitted disease patients were screened for the presence of HIV antibodies by a rapid assay and a commercial enzyme-linked immunosorbent assay. All reactive specimens were confirmed and discriminated by a line immunoassay, and were further tested for the presence of HIV-1 group O antibodies. Our results were compared to data reported in previous studies in Kinshasa. RESULTS Of a total 1970 samples collected, 219 (11.1%) were HIV-1-reactive and seven (0.3%) were dually reactive to HIV-1 and HIV-2. No case of HIV-1 group O or HIV-2 infection was diagnosed. HIV seroprevalence in pregnant women was 3.1% (16 out of 511), 6.3% (19 out of 300) and 1.5% (one out of 65) in Kinshasa, Mbuji-Mayi, and Bwamanda, respectively. HIV seroprevalence in tuberculosis patients was 26% (52 out of 200), 28% (17 out of 60), and 35.3% (29 out of 83), respectively. HIV seroprevalence among blood donors was 3.1% in Kinshasa and 2.8% in Mbuji-Mayi. Compared with data from previous studies performed in Kinshasa, no substantial change in HIV infection rates was observed among the selected population groups. CONCLUSIONS Our results show that HIV prevalence rates have remained relatively unchanged in selected populations despite the political instability and poor environment observed since 1991 in DRC. It also shows the presence, still at very low rate, of dual HIV-1/HIV-2 seropositivity and a growing problem of HIV infection in rural areas. In contrast to other Central African countries, no HIV-1 group O infections were detected in DRC.