Co-circulation of different genotype, sub-genotype and serotypes of hepatitis B virus (HBV) and its epidemiology in Assam: A north-eastern state of India

Purpose: Hepatitis B virus (HBV) infection is a global health problem. HBV has different genotypes and subgenotypes with geographical distinctiveness. Aims: To study the molecular epidemiology and distribution pattern of HBV in Assam; a distinct state of India that may have different genotypic divergence. Settings and design: Patients attending a tertiary care hospital susceptive of Hepatitis B were included, irrespective of age and sex in different agro-climatic zones of Assam. Methods: Samples positive for Hepatitis B surface antigen test and COBAS (R) TaqMan (R) HBV tests were further confirmed by PCR and sequencing followed by phylogenetic analysis. Statistical analysis used: Chi-square test was used to determine whether there was a significant difference among the results in this study. Results: An increase trend of HBV positive cases has been observed in the state. The incidence in female was lower than that of male and age group 26-35 years was most vulnerable. Genotype D, subgenotype D2 and serotype ayw3 were predominant genotype, subgenotype and serotype. The prevalence of subgenotype C3 was a new finding. Phylogenetic analysis showed that the genotypes of HBV prevailing in the state have close relationship with neighboring countries of India which may be due to increased cross border migration of population Conclusions: This comprehensive study of HBV in Assam described the distribution of HBV genotypes and subgenotypes and serotypes in different agro-climatic zones of Assam. These findings will help to formulate the roadmap for prevention and control of the disease as well as targeted therapy of HBV in this State.