Prevalence of hepatitis B virus genotypes and sub-genotypes in north and east regions of India: DNA sequencing methodology

Introduction: Hepatitis B virus (HBV) is a highly prevalent infecting virus among liver-related diseases. The genetic distribution and identification of HBV genotypes and sub-genotypes represented a challenge to control the spread of infection. To find out molecular prevalence, the present methodology was carried out for the distribution pattern of HBV genotypes and subgenotypes in north and east regions of India. Methods:A total of 67 HBV DNA positive subjects were studied. At first, the DNA samples for HBV positive cases were screened by Real-time PCR, and then the selected region of HBV polymerase gene was amplified for the sequence analysis to determine genotypes and sub-genotypes. Results:The prevalent genotype found was the genotype D (62.68%), followed by genotype A (29.85%), and genotype C (7.46%). Subgenotype C1 was identified in the east region only. The frequency of sub-genotype A1 was higher in the north region (n = 13, 30.95%) followed by east region (n = 7, 28%). HBV sub-genotype D1 was found to be predominant in 15 (35.71%) subjects followed by sub-genotypes D2 in 10 (23.80%) subjects from the north region. HBV sub-genotype D2 was found to be predominant in 8 (32%) subjects from the east region. Conclusions:In conclusion, the method clearly demonstrates the high prevalence of subgenotypes D1, D2, A1 in this region. Also, the identification of the sub-genotype C1 in the east region emphasizes the high transmission infection risk and transmission route towards other regions of India.