Shift in the hepatitis B virus genotype distribution in the last decade among the HBV carriers from eastern India: possible effects on the disease status and HBV epidemiology.

In a previous study from eastern India, the prevalence of HBV/C has been increasing among the blood donors. In order to analyze whether there has been any shift in HBV genotype distributions in recent years, the HBV genotypes prevalent during the periods 2000-2002 (Group-I; n=176) and 2007-2009 (Group-II; n=203) were compared, with special attention to changes in the proportion of HBV/C. The rate of prevalence of the three HBV genotypes (A, C, and D; percent prevalence 19.9/21.6/58.5 in Group-I vs. 31.0/28.6/40.4 in Group-II) underwent significant changes with increases in HBV/A and HBV/C among the HBV carriers (0.002). Among the asymptomatic carriers, the prevalence of these two genotypes (P=0.021 for HBV/A and P=0.005 for HBV/C) was significantly high. A notable increase was also observed among the chronic liver disease cases. HBV/A increased significantly among the older age Groups (≥ 51 years), whereas the increase of HBV/C was significant among the younger age Groups (≤ 20 years). With the increase of HBV/A and HBV/C, the rates of basal core promoter double mutation (1762T/1764A) also increased considerably. Binary logistic regression analysis revealed that both HBV/A and 1762T/1764A mutations are predictors of chronic liver disease state over asymptomatic carrier state. Thus, this study highlights the possible influence of HBV genotype shift on the changing scenario of HBV epidemiology and disease in the population.