Genotype distribution of hepatitis B virus in a subset of infected young people in Central Nigeria

Abstract

Ten genotypes (A–J) of hepatitis B virus (HBV) with distinct geographical distribution have been identified as a result of the high degree of genetic heterogeneity of the virus; with Nigeria being the most likely origin of genotype E. HBV genotypes play critical roles in response to antiviral therapy. However, the circulating genotypes of the virus in an HBV-endemic Nigeria are not well understood. In this study, we evaluated the genotypes of HBV amongst a subset of infected young people in Central Nigeria. A total of 350 sera were analysed. All the samples that tested positive for both HBsAg and HBeAg were genotyped by PCR using type-specific primers. A total of 29 cases (8.3%) were both HBsAg and HBeAg positive. Of these, 4 (13.8%) were genotype A (HBV/A), 10 (34.5%) genotype B (HBV/B) and 13 (44.8%) genotype E (HBV/E); suggesting that genotype E was predominant. Additionally, 2 (6.9%) had mixed infection with genotypes B and E. Age and gender were not associated with genotype distribution (P > 0.05). This is the first report of genotype B as a circulating variant in Nigeria. These findings have critical national and regional implications for the epidemiology of the virus, vaccination, antiviral therapy and clinical outcomes. Keywords: Hepatitis B, HBV genotype, Nigeria