Hepatitis B and C Virus Infections in the Three Pygmy Groups in Cameroon

Abstract

A high (11.8%) level of hepatitis B virus (HBV) infection was found among 524 Pygmies in Cameroon, whereas the extent of hepatitis C virus (HCV) infection in the same population was low (0.6%). Phylogenetic analyses showed cocirculation of two HBV genotypes, HBV-A3 and -E. Taken together, our results suggest different epidemiological scenarios concerning HBV and HCV infections in this population.Sub-Saharan Africa is considered to be an area of high hepatitis B virus (HBV) and hepatitis C virus (HCV) endemicity (6, 11). However, to date little information has been available pertaining to the prevalence and genetic diversity of these viruses in central Africa. In Cameroon, HBV and HCV infections have been studied mostly among Bantu populations (4,13,15), and very few data are available for the Pygmies in this region. The Pygmies have lived in a forest environment in Cameroon for more than 20,000 years, mostly as hunter-gatherers (19). The characterization of HBV and HCV isolates from ancient populations may help to reveal the origin and evolutionary history of these viruses (7). Three distinct Pygmy groups currently live in Cameroon: the Baka, the Bakola, and the Bedzan. Three studies conducted 15 years ago reported a high HCV prevalence, ranging from 6 to 11%, in the Pygmy population (5, 10, 12). However, these studies only considered the Baka. Furthermore, the performances of the tests used at that time are questionable. A more recent study demonstrated an HCV prevalence of only 2.3% (8). In those 4 studies, Cameroon was found to be an area where HBV is highly endemic. Even now, no comparable information is available for the Bakola or Bedzan Pygmies. Thus, the objectives of our study were to assess the prevalence of HBV and HCV markers among the three Pygmy groups from Cameroon and also to study the HBV genetic diversity in these populations.This study formed part of a survey of viral emergence in Pygmies from Cameroon conducted from 2005 to 2008 (1-3). Informed consent was obtained from adults (or from parents, in the case of children) before blood sampling. Furthermore, the participants of the study underwent a medical examination and, if necessary, were treated according to local procedures on site or were sent to local medical facilities. The geographic localization, the number of subjects included in each group, the mean age, and the sex ratio are shown in Fig. 1A.The presence of antibodies against HCV (anti-HCV) was checked by the use of a third-generation enzyme immunoassay (EIA) (Monolisa anti-HCV Plus version 2; Bio-Rad, MarneLa-Coquette, France). A positive result for anti-HCV was defined as a Monolisa ratio of greater than 6 (16). Of the 346 available samples tested, only 2 (0.6%) (one Baka and one Bedzan; 95% confidence interval [CI], 0.9 to 1.9%) were anti-HCV positive. Those samples were negative when tested for HCV RNA.HBV surface antigen (HBsAg) was screened for by a thirdgeneration EIA (Monolisa AgHBs Plus; Bio-Rad). Of the 524 samples tested, 62 (11.8%) (95% CI, 9.2 to 14.9%) were positive. Th...

Molecular identification of hepatitis B virus genotypes/subgenotypes: Revised classification hurdles and updated resolutions

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Prevalence of HBs Antigen, and HCV and HIV Antibodies in a Young Male Population in Cameroon

“…In Cameroon, according to a review of literature published between 1985 and 2014 concerning studies on sentinel populations (blood donors, pregnant women, health workers, Pygmies), prevalence ranges between 6.1% and 25.3% [2] [3] for hepatitis B virus (HBV), and 0.6% and 21% for hepatitis C virus (HCV) [4] [5].…”

Application of PCR Technologies to Humans, Animals, Plants and Pathogens from Central Africa

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