PCR-Based Detection of Hepatitis B Virus Genotypes Among Blood Donors at the University of Calabar Teaching Hospital

Hepatitis B virus (HBV) infection remains a significant public health burden in sub-Saharan Africa, with Nigeria among the highest-prevalence countries globally. Genotype characterization of HBV is important because distinct genotypes influence disease progression, treatment response, and vaccine efficacy. This study employed PCR-based methods to detect and genotype HBV among blood donors at the University of Calabar Teaching Hospital, Cross River State, South-South Nigeria. Blood samples from 250 HBsAg-reactive donors were subjected to viral DNA extraction using a commercial silica column kit. Nested PCR was used for HBV DNA amplification, followed by genotyping using genotype-specific primers for genotypes A through H. Sanger sequencing of surface gene amplicons was performed for phylogenetic confirmation. HBV DNA was detectable in 74% of HBsAg-reactive donors. Genotype E predominated (68%), followed by genotype A (22%), consistent with established West African patterns. Occult HBV infection was detected in 12% of HBsAg-negative blood units, highlighting a risk to transfusion safety. The study recommends supplementary nucleic acid testing (NAT) in blood banks to reduce transfusion-transmissible HBV risk. Keywords: hepatitis B virus, genotype, blood donors, PCR, Calabar.