Circulating HBV Genotypes among Animal and Non-Animal Handlers in Osun State, Nigeria

Aim: Hepatitis B virus (HBV) is not uncommon among animal and non-animal handlers. The brutality of HBV infection and the outcome of treatment is linked with exact HBV genotypes. No study on the circulation of HBV genotypes has been reported among animal and non-animal handlers in Nigeria. This study was intended to evaluate the genotypic distribution among animal and non-animal handlers in Osun State, Nigeria. Study Design:  Cross-sectional study. Place and Duration of Study: Ladoke Akintola University of Technology (LAUTECH), Nigeria, between June 2015 and July 2019. Methods: Blood samples were obtained from HBsAg positive individuals and screened for HBV-DNA from cohorts of animal and non-animal handlers. HBV-DNA was extracted, amplified and genotyped using a multiplex PCR technique with primers specific for six genotypes of HBV (Genotype A, B, C, D, E and F). Results: Results showed that a total of 11 (6.1%) of the 180 animal and non-animal handlers evaluated were positive to HBsAg and 4.4% were positive for HBV-DNA by a semi-nested PCR using HBV specific primer pairs. The molecular analysis of the sera of 11 HBsAg positive animal and non-animal handlers showed that 72.7% of them had a true HBV infection. Results further show that genotype E (75.0%) was predominant over genotype A (12.5%) and mix genotypes (D and E) with 12.5% prevalence. Other genotypes were not detected. Of the 8 positive HBV-DNA samples, 7 (87.5%) were males and one (12.5%) was a female. All animal and non-animal handlers with true HBV infection were found to harbour HBV genotype E predominantly. Conclusion: The molecular analysis of HBV-DNA and genotypes circulating among animal and non-animal handlers shows that the majority of the subjects with true HBV infection were found to predominantly harbour HBV genotype E in Osun state, Nigeria. The study further highlights the predominance HBV genotype E in Nigeria.