Molecular identification of genotypes of Hepatitis B virus in Borno State, Nigeria

Hepatitis is a significant disease of the liver caused by different genotypes of hepatitis B virus. Neonates delivered of HBsAg and HBeAg positive mothers are most susceptible. The sequelae of infection and prognosis vary with the age of patient infected and the genotype (A-J) of the virus involved. These genotypes have 7.5 to 8% difference in their genomic sequences. This study was aimed at identifying the genotypes among hepatitis B surface antigen positive individuals. Four hundred and ten blood samples were randomly collected in a hospital-based cross sectional study. Sera samples were obtained for qualitative identification of the serological markers of hepatitis B virus (HBsAg, Anti-HBs, HBeAg, Anti-HBe and Anti-HBc) using rapid chromatographic immunoassays test kit (Qingdao Hightop Biotech Co., China). However, 34 presumptive hepatitis B surface antigen positive samples were assayed by polymerase chain reaction (PCR) using universal outer primer for identification of all HBV genotypes. Nested polymerase chain reaction assay was performed to determine genotype composition of the positive samples. The outcome of the molecular analysis of the 34 positive samples showed that 9 (26.5%) were positive comprising only 2 genotypes (B and E) which presented in mixed infections. Hepatitis B virus genotypes B and E were identified. The identification of genotype E corroborates reports of its existence in the West African region. However, the identification of genotype B in West Africa region is novel.