title: Geographic distribution of hepatitis C virus genotype 6 subtypes in Thailand.
abstract: The nucleotide sequence of hepatitis C virus (HCV) genotype 6 found mostly in south China and south-east Asia, displays profound genetic diversity. The aim of this study to determine the genetic variability of HCV genotype 6 (HCV-6) in Thailand and locate the subtype distribution of genotype 6 in various geographic areas. Four hundred nineteen anti-HCV positive serum samples were collected from patients residing in - the central part of the country. HCV RNA positive samples based on reverse transcriptase- polymerase chain reaction (RT-PCR) of the 5'UTR were amplified with primers specific for the core and NS5B regions. Nucleotide sequences of both regions were analyzed for the genotype by phylogenetic analysis. To determine geographic distribution of HCV-6 subtypes, a search of the international database on subtype distribution in the respective countries was conducted. Among 375 HCV RNA positive samples, 71 had HCV-6 based on phylogenetic analysis of partial core and NS5B regions. The subtype distribution in order of predominance was 6f (56%), 6n (22%), 6i (11%), 6j (10%), and 6e (1%). Among the 13 countries with different subtypes of HCV-6, most sequences have been reported from Vietnam. Subtype 6f was found exclusively in Thailand where five distinct HCV-6 subtypes are circulating. HCV-6, which is endemic in south China and south-east Asia, displays profound genetic diversity and may have evolved over a considerable period of time.
authors.affiliation: Faculty of Medicine, Center of Excellence in Clinical Virology, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Srunthron
authors.initials: S
authors.lastname: Akkarathamrongsin
authors.forename: Kesmanee
authors.initials: K
authors.lastname: Praianantathavorn
authors.forename: Nisachol
authors.initials: N
authors.lastname: Hacharoen
authors.forename: Apiradee
authors.initials: A
authors.lastname: Theamboonlers
authors.forename: Pisit
authors.initials: P
authors.lastname: Tangkijvanich
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami
authors.forename: Yong
authors.initials: Y
authors.lastname: Poovorawan
mesh_terms: D020121:5' Untranslated Regions; D005838:Genotype; D005843:Geography; D016174:Hepacivirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006526:Hepatitis C / Q000453:epidemiology* / Q000821:virology*; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D012367:RNA, Viral / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013785:Thailand / Q000453:epidemiology
chemical_list: D020121:5' Untranslated Regions; D012367:RNA, Viral