Journal of Medical Virology 85:1340–1347 (2013) 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 Avik Biswas, 1 Rajesh Panigrahi, 1 Manisha Pal, 2 Subhasis Chakraborty, 3 Prasun Bhattacharya, 3 Shekhar Chakrabarti, 4 and Runu Chakravarty 1 * 1 ICMR Virus Unit, ID & BG Hospital Campus, Kolkata, India 2 Department of Statistics, University of Calcutta, Kolkata, India 3 Institute of Blood Transfusion Medicine and Immunohematology, Kolkata, India 4 National Institute of Cholera and Enteric Diseases, Kolkata, India 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 ¼ 176) and 2007–2009 (Group-II; n ¼ 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 ¼ 0.021 for HBV/A and P ¼ 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 re- gression 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. J. Med. Virol. 85:1340– 1347, 2013. # 2013 Wiley Periodicals, Inc. KEY WORDS: HBV genotype shift; HBV epi- demiology; HBV genotypes; alteration in disease status INTRODUCTION Despite the availability of an effective vaccine, hepatitis B virus (HBV) infection continues to be a substantial global health problem, with an estimated 400 million chronic carriers worldwide. HBV infection can cause diverse clinical outcomes ranging from asymptomatic carriage, self-limiting acute hepatitis, fulminant hepatic failure, chronic liver disease, cir- rhosis and hepatocellular carcinoma (HCC) [Schaefer, 2005]. So far eight HBV genotypes (A–H) [Schaefer, 2007] have been well characterized, which show distinctive geographical distribution [Schaefer, 2005]. The preva- lence of HBV genotypes in any geographical location or population has significant correlation with the epidemiology, and particularly with the disease sta- tus [Kay and Zoulim, 2007]. Although the complex co-ordination of viral, host and environmental factors determine the degree of disease severity, several comparative studies indicat- ed that prevalence of HBV genotypes in a given population can be linked with differential clinical manifestations [Tanaka and Mizokami, 2007; Cao, 2009]. It has been pointed out that a particular genotype can become dominant over the others in the Grant sponsor: Indian Council of Medical Research, New Delhi; Grant sponsor: Council of Scientific & Industrial Research (CSIR), New Delhi (to A.B.); Grant sponsor: Indian Council of Medical Research (ICMR), New Delhi (to R.P.). Conflicts of interest: None to declare. *Correspondence to: Runu Chakravarty, ICMR Virus Unit, GB 4, 1st Floor, ID & BG Hospital Campus, 57 Dr. Suresh Chandra Banerjee Road, Kolkata 700010, India. E-mail: runugc@yahoo.co.uk Accepted 18 March 2013 DOI 10.1002/jmv.23628 Published online in Wiley Online Library (wileyonlinelibrary.com).  C 2013 WILEY PERIODICALS, INC.