Prevalence of anti-HBV seromarkers and genotypic characterization of hepatitis B virus among antenatal care attendees in Eritrea

Abstract

Mother-to-child transmission (MTCT) of hepatitis B virus (HBV) is a major cause of chronic HBV infection. Therefore understanding the epidemiology of HBV infection among pregnant women is critical to prevent MTCT. The aim of this study was to assess the seroprevalence of anti-HBV markers and determine circulating HBV genotypes among women seeking antenatal care within different health facilities in Eritrea. This cross-sectional study was conducted on archived patient samples and records collected during the 2016 antenatal care HIV sentinel surveillance. A total of 5009 samples were screened for anti-HBc and anti-HBs seromarkers using Enzyme Linked Immunosorbent Assay (ELISA) technique. Viral DNA was then extracted from the HBsAg positive samples using Qiagen® Miniviral DNA isolation kit and the HBV-S gene amplified by nested PCR. The amplified PCR product was sequenced and from the generated sequences genetic diversity determined using MEGA v7. The socio-demographic and serological data were analysed using SPSS version 21. Pearson’s Chi-square tests were used to measure the strength of association. The threshold for statistical significance was set at p < 0.05. The mean age of the women was 26.7 ±5.9 years and findings of the socio-demographic data showed that 92.6% of the women were married with 88.4% being housewives. Approximately 70% of the women had attended formal education. Results of the serological markers showed that 25.8% (1241) were positive for anti-HBc and the anti-HBs marker seroprevalence was 14.2% (706). The HBV exposure rate exhibited marked differences among the zobas (regions) ranging from 15.5% to 29.1% and this difference was statistically significant with p-value < 0.001. The phylogenetic analysis revealed presence of HBV variants with genotype A 77.8% (32), D 20% (9) and E 2.2% (1). Findings of the study revealed a substantial exposure to HBV among pregnant women indicated by 25.8% prevalence of anti-HBc. Further the anti-HBs rate stands at 14.2% with the prevalence of vaccine induced anti-HBs at 5.3%. In light of this immunization against HBV therefore remains key to prevention and mitigation of HBV in the Eritrean population. The study provided the first description of HBV genetic diversity in Eritrea confirming presence of genotypes A, D and E. This demonstrates that there could be a high genetic diversity of HBV in Eritrea.