Bui Thi Ton Taht, Tran Tan Thanh, Nghiem My Ngoc, Rahman Pierre, Tran Thi Thanh Thanh, Dinh Man Nguyen Huy, Le Manh Hung, Nguyen Van Vinh Chau, Thwaites Guy, Rahman Motiur
Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam.
Oxford University Clinical Research Unit, Toronto, Canada.
BMC Infect Dis. 2017 Aug 31;17(1):601. doi: 10.1186/s12879-017-2697-x.
Hepatitis B virus (HBV) infection is a major public health problem globally. HBV genotypes and subgenotypes influence disease transmission, progression, and treatment outcome. A study was conducted among treatment naive chronic HBV patients in southern Vietnam to determine the genotypes and subgenotypes of HBV.
A prospective, exploratory study was conducted among treatment naïve chronic HBV patients attending at the Hospital for Tropical Diseases, in Ho Chi Minh City, Vietnam during 2012, 2014 and 2016. HBV DNA positive samples (systematically selected 2% of all treatment naïve chronic patients during 2012 and 2014, and 8% of all treatment naïve chronic patients during 2016) were subjected to whole genome sequencing (WGS) either by Sanger or Illumina sequencing. WGS was used to define genotype, sub-genotype, recombination, and the prevalence of drug resistance and virulence-associated mutations.
One hundred thirty five treatment naïve chronic HBV patients including 18 from 2012, 24 from 2014, and 93 from 2016 were enrolled. Of 135 sequenced viruses, 72.6% and 27.4% were genotypes B and C respectively. Among genotype B isolates, 87.8% and 12.2% were subgenotypes B4 and B2 respectively. A G1896A mutation in the precore gene was present in 30.6% of genotype B isolates. The genotype C isolates were all subgenotype C1 and 78.4% (29/37) of them had at least one basal core promoter (BCP) mutation. A1762T and G1764 T mutations and a double mutation (A1762T and G1764 T) in the BCP region were significantly more frequent in genotype C1 isolates (p < 0.001).
HBV genotype B including subgenotype B4 is predominant in southern Vietnam. However, one fourth of the chronic HBV infections were caused by subgenotype C1.
乙型肝炎病毒（HBV）感染是全球主要的公共卫生问题。HBV基因型和亚基因型影响疾病传播、进展及治疗结果。在越南南部未接受过治疗的慢性HBV患者中开展了一项研究，以确定HBV的基因型和亚基因型。
于2012年、2014年和2016年在越南胡志明市热带病医院对未接受过治疗的慢性HBV患者进行了一项前瞻性探索性研究。对HBV DNA阳性样本（2012年和2014年系统选取所有未接受过治疗的慢性患者的2%，2016年选取所有未接受过治疗的慢性患者的8%）采用桑格测序法或Illumina测序法进行全基因组测序（WGS）。WGS用于确定基因型、亚基因型、重组情况以及耐药性和毒力相关突变的流行情况。
纳入了135例未接受过治疗的慢性HBV患者，其中2012年的18例，2014年的24例，2016年的93例。在135株测序病毒中，分别有72.6%和27.4%为B型和C型基因型。在B型基因型分离株中，分别有87.8%和12.2%为B4和B2亚基因型。前核心基因中的G1896A突变存在于30.6%的B型基因型分离株中。C型基因型分离株均为C1亚基因型，其中78.4%（29/37）至少有一个基本核心启动子（BCP）突变。BCP区域的A1762T和G1764T突变以及双重突变（A1762T和G1764T）在C1基因型分离株中明显更常见（p < 0.001）。
包括B4亚基因型在内的B型HBV在越南南部占主导地位。然而，四分之一的慢性HBV感染由C1亚基因型引起。
