Treatment of trypanosomiasis before 1951 may have caused iatrogenic HCV transmission. Population-wide half-yearly intramuscular pentamidine for trypanosomiasis chemoprophylaxis in 1947-1953 may have caused iatrogenic HTLV-1 transmission. These and other interventions against tropical diseases could have iatrogenically transmitted SIV(cpz), jump-starting the HIV-1 epidemic. The excess mortality among patients with trypanosomiasis treated before 1951 supports this hypothesis.

The molecular epidemiology of hepatitis C virus (HCV) in the Central African Republic (CAR) is poorly documented. Thus, we conducted phylogenetic analyses of NS5B gene sequences from 58 HCV-infected inhabitants of a remote area of south-west CAR, which indicated that 48 (82.8 %) were infected with genotype 4 (HCV-4), five (8.6 %) with genotype 2 and five (8.6 %) with genotype 1. HCV-4 strains were highly heterogeneous, containing previously described subtypes 4k (48 %), 4c (27 %), 4r (4 %), 4f (4 %) and unclassified subtypes (17 %). To estimate the epidemic history of these HCV-4 strains, an evolutionary analysis using the coalescent approach was used. The estimated date of the most recent common ancestor of the CAR HCV-4 strains was 1539 (95 % confidence intervals, 1317-1697). They exhibited a rapid, exponential spread from 1935 to 1965, simultaneously with what was recently reported in neighbouring Cameroon and Gabon. The hypothesis of a massive iatrogenic transmission during interventions for the control of endemic tropical diseases is discussed.

Heterosexual transmission of hepatitis C virus (HCV) is uncommon, with few studies undertaken in Central Africa. To determine the frequency of inter-spouse HCV transmission, cross-sectional studies of elderly individuals in Ebolowa, Cameroon and Nola, Central African Republic, in which, respectively, 24 and 83 long-term couples had been identified, were examined further. Blood samples were tested for antibody to HCV. Anti-HCV positive samples were genotyped by phylogenetic analysis of a fragment of the NS5B gene. In Nola, 4 out of 9 (44.4%) wives of anti-HCV positive husbands and 1 out of 74 (1.4%) wives of anti-HCV negative husbands were anti-HCV positive (P < 0.001); in Ebolowa, the corresponding proportions were 10 out of 15 (66.7%) and 3 out of 9 (33.3%) (P = 0.21). After adjustment for age and site-specific risk factors of HCV infection, HCV seropositivity of the wives remained associated with their husbands' HCV serostatus, significantly so in Nola (P = 0.003) and marginally in Ebolowa (P = 0.06). In 7 out of 14 concordant seropositive couples, the genotype could be determined in both spouses. Four couples were infected with different genotypes, while three were infected with the same genotype. Thus, serological concordance between the spouses was related to a combination of infections acquired independently and inter-spouse transmission. It could not be determined whether inter-spouse transmission occurred sexually, through blood-blood contact, or otherwise. Inter-spouse transmission may have contributed to the high prevalence among elderly populations of Central Africa since some patients infected during healthcare subsequently transmitted the virus to their spouse.