title: A description of the hepatitis B virus genomic background in a high-prevalence area in China.
abstract: BACKGROUND
  Hepatitis B (HB) is an important disease worldwide. Almost 350 million people are positive for Hepatitis B virus surface antigen (HBsAg), and one-third of them live in China. According to a nation-wide serosurvey in China in 2006, the prevalence of HBsAg was higher in Northwest China than in other areas. However, the epidemic HBV strains in this area are poorly studied.
  
  
  RESULTS
  In this study, 242 complete hepatitis B virus (HBV) genome sequences were obtained from HBV asymptomatic carriers in major cities of Northwest China. The 242 HBV sequences clustered into genotypes B, C and D. Through comparison of the genotype consensus sequences, 158 genotype-dependent positions were observed in P, S and X ORFs. Clinically relevant mutation screening in this study revealed that no HBV antiviral drug resistance mutations were observed and the vaccination failure mutations were heavily underrepresented.
  
  
  CONCLUSIONS
  The role of genotype D strains in HBV prevalence should not be ignored in Northwest China. Due to low prevalence of vaccination failure mutations, it can be inferred that the genotype B, C and D strains in Northwest China may have less likelihood of vaccine escape.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Chen
authors.forename: Jie
authors.initials: J
authors.lastname: Gao
authors.forename: Zhaohua
authors.initials: Z
authors.lastname: Ji
authors.forename: Weilu
authors.initials: W
authors.lastname: Zhang
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Rui
authors.initials: R
authors.lastname: Xu
authors.forename: Jingxia
authors.initials: J
authors.lastname: Zhang
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.forename: Shi
authors.initials: S
authors.lastname: Li
authors.forename: Shijie
authors.initials: S
authors.lastname: Hu
authors.forename: Lei
authors.initials: L
authors.lastname: Shang
authors.affiliation: Department of Epidemiology, School of Public Health, Fourth Military Medical University, No, 17, Changle west RD, Xi'an 710032, China. zhjshao@hotmail.com.
authors.forename: ZhongJun
authors.initials: Z
authors.lastname: Shao
authors.forename: Yongping
authors.initials: Y
authors.lastname: Yan
mesh_terms: D000293:Adolescent; D000328:Adult; D002353:Carrier State / Q000453:epidemiology / Q000821:virology; D002681:China / Q000453:epidemiology; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics*; D005260:Female; D014644:Genetic Variation; D016679:Genome, Viral; D005838:Genotype; D006509:Hepatitis B / Q000453:epidemiology* / Q000821:virology*; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D015995:Prevalence; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D004279:DNA, Viral