Risk Factors for Hepatitis C Virus Transmission in Colonial Cameroon

Department of Microbiology and Infectious Diseases, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Clinical Infectious Diseases (Impact Factor: 8.89). 10/2010; 51(7):768-76. DOI: 10.1086/656233
Source: PubMed


In southern Cameroon, where SIV(cpz), the source of human immunodeficiency virus 1 (HIV-1) group M, is prevalent among wild chimpanzees, approximately 50% of some human birth cohorts have been infected with hepatitis C virus (HCV) through unclear mechanisms.
To evaluate indirectly the hypothesis that medical interventions contributed to the early emergence of HIV-1, we conducted a cross-sectional study of 451 inhabitants of Ebolowa in southern Cameroon aged 60 years, using HCV as a marker of parenteral transmission of blood-borne viruses. We administered a questionnaire and tested serum for antibodies against HCV. Viral gene sequences were obtained from HCV-positive sera. Molecular clock analyses provided an independent source of information on epidemic history.
A total of 252 participants (56%) were HCV seropositive. HCV sequences were amplified and genotyped from 171 individuals. Independent risk factors for HCV seropositivity were older age, having received intravenous treatment against malaria, and having attended an ethnic school (women only), whereas having been circumcised by a traditional practitioner (men only) tended to be associated with HCV. In addition, transfusions were associated with HCV genotype 1 transmission. Molecular clock analyses of HCV genotypes 1, 2, and 4 revealed that each independently underwent exponential growth during the first half of the 20th century.
Medical interventions (intravenous antimalarial drugs, transfusions) and to a lesser extent traditional practices (circumcision) were associated with the massive transmission of HCV among this population decades ago. This finding supports the hypothesis that medical interventions contributed to the transmission of blood-borne viruses, perhaps including SIV(cpz) and HIV-1, in the same region during the early 20th century.

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    • "However, the genetic diversity of HCV in the DRC is not as high as that in other central African countries where various subtypes of multiple HCV genotypes are sometimes observed (e.g. genotypes 1, 2 and 4 in Cameroon; Ndjomou et al., 2003, Pépin et al., 2010a). Further, we failed to detect any genotype 7 isolates despite using the same primers as those used to initially discover the strain (Murphy et al., 2007b), indicating that the prevalence of genotype 7 within the DRC is low. "
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    ABSTRACT: HCV genotype 4 is prevalent in many African countries, yet little is known about the genotype׳s epidemic history on the continent. We present a comprehensive study of the molecular epidemiology of genotype 4. To address the deficit of data from the Democratic Republic of the Congo (DRC) we PCR amplified 60 new HCV isolates from the DRC, resulting in 33 core- and 48 NS5B-region sequences. Our data, together with genotype 4 database sequences, were analysed using Bayesian phylogenetic approaches. We find three well-supported intra-genotypic lineages and estimate that the genotype 4 common ancestor existed around 1733 (1650–1805). We show that genotype 4 originated in central Africa and that multiple lineages have been exported to north Africa since ~1850, including subtype 4a which dominates the epidemic in Egypt. We speculate on the causes of the historical intra-continental spread of genotype 4, including population movements during World War 2.
    Full-text · Article · Jan 2015 · Virology
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    • "In southern Cameroon, where west-central African chimpanzee strains of simian immunodeficiency virus, the source of HIV-1 group M, is prevalent among wild chimpanzees, ≈50% of some human birth cohorts were infected with HCV through unclear mechanisms (29) but suggesting high levels of iatrogenic transmission (30). Some have speculated that this level of iatrogenic transmission jump-started the HIV/AIDS pandemic through injection treatment of trypanosomiasis before 1951 (31). "
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    ABSTRACT: Pediatric infectious disease clinicians in industrialized countries may encounter iatrogenically transmitted HIV, hepatitis B virus, and hepatitis C virus infections in refugee children from Central Asia, Southeast Asia, and sub-Saharan Africa. The consequences of political collapse and/or civil war-work migration, prostitution, intravenous drug use, defective public health resources, and poor access to good medical care-all contribute to the spread of blood-borne viruses. Inadequate infection control practices by medical establishments can lead to iatrogenic infection of children. Summaries of 4 cases in refugee children in Australia are a salient reminder of this problem.
    Full-text · Article · Jun 2013 · Emerging Infectious Diseases
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    • "The possible cause or causes of past iatrogenic HCV transmission in sub-Saharan Africa are more complex and less well understood (reviewed in Pépin, 2011). In Ebolowa, Cameroon, Pépin et al. (2010b) found that HCV seropositivity was associated with past intravenous treatment for malaria, but not with antitreponemal treatment, as previously suspected (Pépin and Labbé, 2008). While HCV can be transmitted through sexual or intrafamilial routes, past iatrogenic transmission better explains why HCV seropositivity varies greatly among locations within a country (Frank et al., 2000; Nerrienet et al., 2005) as well as its elevation in those aged >50 in affected locations. "
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    ABSTRACT: The prevalence and genetic diversity of hepatitis C virus (HCV) and human pegivirus (HPgV) in many regions of sub-Saharan Africa is poorly characterized, including in the Democratic Republic of Congo - the largest country in the region and one of the most populous. To address this situation we conducted a molecular epidemiological survey of HCV and HPgV (previously named GB Virus C or hepatitis G virus) in samples collected in 2007 from 299 males from the DRC, whose ages ranged from 21 to 71years old. Samples were tested for the presence of HCV antibodies by ELISA reactive samples were subsequently tested for HCV RNA using RT-PCR in which both the HCV Core and NS5B genome regions were amplified. Remaining samples were tested for HPgV RNA and the HPgV NS3 genome region of positive samples was amplified. For HCV, 13.7% of the samples were seropositive (41/299) but only 3.7% were viremic (11/299). HPgV RNA was found in 12.7% (33/259) of samples. HCV viremia was strongly associated with age; the percentage of samples that contained detectable HCV RNA was ∼0.5% in those younger than 50 and 13% in those older than 50. Our study represents the first systematic survey of HCV genetic diversity in the DRC. HCV sequences obtained belonged to diverse lineages of genotype 4, including subtypes 4c, 4k, 4l and 4r, plus one unclassified lineage that may constitute a new subtype. These data suggest that HCV in the DRC exhibits an age 'cohort effect', as has been recently reported in neighbouring countries, and are consistent with the hypothesis that HCV transmission rates were higher in the mid-twentieth century, possibly as a result of parenteral, iatrogenic, or other unidentified factors. Different HCV subtypes were associated with individuals of different ages, implying that HCV infection in the DRC may have arisen through multiple separate HCV epidemics with different causes.
    Full-text · Article · Feb 2013 · Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases
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