Distribution of hepatitis B virus genotypes in general population of Myanmar via Nation wide study

Abstract

Background Hepatitis B virus (HBV) infection is a severe health concern worldwide. HBV is a DNA virus with a rapid rate of mutation. Based on the heterogeneity of the HBV nucleotide sequence, the HBV strains are divided into ten genotypes, A to J, with a characteristic geographical distribution. Identifying and tracking the changes of HBV genotypes is important in epidemiological and transmission studies, predicting the risk for the development of severe liver disease and response to antiviral treatment. The present study was conducted to detect HBV genotypes and sub-genotypes in general population of different states and regions in Myanmar.

Methods A total of 5,547 general adult population who residing at seven states, seven regions and Nay Pyi Taw Union Territory were screened for Hepatitis B Surface antigen (HBsAg) by Immunochromatgraphic test (ICT) in 2015. Of 353 HBsAg positive samples, HBV DNA were detected by using polymerase chain reactions (PCR) targeting the DNA sequences encoding the Pre-S region. A total of 153 PCR positive samples were preceded for genotyping by partial genome sequencing of both directions. The resulting sequences were then edited, aligned and compared with reference sequences using National Centre for Biotechnology Information (NCBI) web based genotyping tool.

Results Three HBV genotypes; HBV/ C, HBV/ D and HBV/ B were detected in Myanmar, in which genotype HBV/ C (66.7%) was the most prevalent genotype followed by HBV/ D (32%) and HBV/ B (1.3%) respectively. Sub-genotyping revealed a total of 7 sub-genotypes within genotypes B, C and D: two (B4 and B5) in HBV/ B, three (C1, C5 and C7) in HBV/C and two (D3 and D6) in HBV/ D.

Conclusion Genotype HBV/C, sub-genotype C1 was the most predominant genotype distributed in all states and regions of Myanmar. This study was first report on Nation- wide distribution of HBV genotype and sub-genotypes in Myanmar and the findings will be a huge support for hepatitis disease surveillance programme which is the one of the National Priority Diseases in Myanmar.