Hepatitis C virus prevalence and genetic diversity among pregnant women in Gabon, central Africa

Abstract

Background: Hepatitis C virus (HCV) infection is a major global public health problem in both developed and developing countries. The prevalence and genetic diversity of HCV in pregnant women in Gabon, central Africa, is not known. We therefore evaluated the prevalence and the circulating genotypes of HCV in a large population cohort of pregnant women.

Methods: Blood samples (947) were collected from pregnant women in the five main cities of the country. The prevalence was evaluated by two ELISA tests, and the circulating genotypes were characterized by sequencing and phylogenetic analysis.

Results: Twenty pregnant women (2.1%) were infected with HCV. The seroprevalence differed significantly by region (p = 0.004) and increased significantly with age (p = 0.05), being 1.3% at 14-20 years, 1.1% at 21-25 years, 1.9% at 26-30 years, 4.1% at 31-35 years and 6.0% at > 35 years. Sequencing in the 5'-UTR and NS5B regions showed that the circulating strains belonged to genotypes 4 (4e and 4c).

Conclusion: We found that the HCV seroprevalence in pregnant women in Gabon is almost as high as that in other African countries and increases with age. Furthermore, only genotype 4 (4e and 4c) was found. More extensive studies aiming to evaluate the prevalence and heterogeneity of HCV genotypes circulating in the general population of the country are needed.

Figure 1

Map of Gabon in central Africa with the selected sentinel sites at which blood was collected from pregnant women.

Figure 2

Phylogenetic analysis of HCV NS5B sequences. A neighbour-joining phylogenetic tree was constructed from Gabonese isolates from pregnant women, and published reference sequences for the various HCV genotypes were obtained from GenBank. The Kimura two-parameter method of estimating genetic distance was used. Numbers next to the nodes of the tree represent bootstrap values (1000 replicates). In genotype 4, sequences found in Gabon are indicated in bold. The GenBank accession numbers of the new NS5b sequences of HCV from Gabon are EU0334530 to EU0334534.