Epidemic History and Iatrogenic Transmission of Blood-borne Viruses in Mid-20th Century Kinshasa

Kinshasa, Democratic Republic of Congo (DRC), is where human immunodeficiency virus type 1 (HIV-1) appears to have most diversified. The factors that lead to jumpstarting the HIV-1 epidemic remain unclear; mounting evidence suggests medical interventions may have contributed. Hepatitis C virus (HCV) and human T-cell lymphotropic virus type 1 (HTLV-1) are viruses compatible with long-term survival but with broadly similar modes of transmission as HIV. The main objective was to assess the association of past intravenous treatment with HCV and HTLV-1 seropositivity. The investigators hypothesized that medical interventions in the mid-20th century may have facilitated the emergence of HIV-1 in central Africa. To assess the association of injectable treatments with HCV and HTLV-1 infection and to reconstruct past virus dynamics, the investigators conducted a cross-sectional study of 839 elderly long-term inhabitants of Kinshasa, with serological assays followed by amplification and sequencing. Risk factors were assessed through logistic regression. Phylogenetic methods were used to reconstruct the epidemic history of HCV.