No abstract

Background: Drug resistance has become a major concern for antiviral therapy in patients with chronic hepatitis B (CHB), leading to an increased risk of treatment failure. We aimed to identify the prevalence of hepatitis B virus (HBV) DNA polymerase mutations and to determine the frequency of HBV genotypes and subgenotypes in treatment-naive patients with CHB in Mekong Delta, Vietnam.Methods: Of the 550 drug-naive CHB patients from Mekong Delta, their serum samples were analyzed for HBV DNA mutations, genotypes, and subgenotypes using polymerase chain reaction sequencing.Results: Of the 550 patients who were infected with either HBV genotype B (72.9%) or genotype C (27.1%), the frequencies of subgenotypes were 19% B1, 3.6% B2, 10.3% B3, 39.8% B4, 0.4% C1, and 26.9% C2. The only mutation that was detected in 54 patients (10.7%) was rtV207M. The rtV207M mutation was found among 13.9% (51/368) of genotype B and among 2.2% (3/137) of genotype C (P < 0.0001).Discussion: Genotype B and subgenotype B4 are predominant in Mekong Delta. Only 1 mutation rtV207M is discovered in our study. These findings suggest that it is unnecessary to test for HBV resistance mutation before delivering antiviral therapy.