title: Phylogenetic analysis of hepatitis A virus in Thailand.
abstract: Human hepatitis A virus (HAV) is a major causative agent of acute hepatitis, and the isolates are categorised into four genotypes: I (GI), II (GII), III (GIII), and VII (GVII). Although viral hepatitis has been detected under a nationwide surveillance system in Thailand, the genetic variation of HAV has not yet been determined. In the present study, serum specimens were collected from acute hepatitis patients in Thailand from 1998-2002. The IgM-class antibody to HAV was detected in 156 out of 394 sera, counting as many as 39.6% of acute viral hepatitis cases. HAV RNA in the serum specimens was amplified by reverse-transcription polymerase chain reaction (RT-PCR), and a phylogenetic analysis of the putative VP1/2A junction of the genome was performed. The isolates were grouped into two genetic groups, GIA and GIB. This is the first report to identify subgenotype IB (GIB) in Thailand. The genetic segregation was closely related to the province where hepatitis A occurred and the serum specimens were collected. In addition, genetically similar strains were identified in both 1998 and 2001-2002 isolates from two close provinces in the southern part of Thailand, suggesting that a strain indigenous to the province or district has been circulating in southern Thailand.
authors.affiliation: Viral Hepatitis Section, National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Nonthaburi 11000, Thailand. naiyanaw@dmsc.moph.go.th
authors.forename: Naiyana
authors.initials: N
authors.lastname: Wattanasri
authors.forename: Kriangsak
authors.initials: K
authors.lastname: Ruchusatsawat
authors.forename: Somsak
authors.initials: S
authors.lastname: Wattanasri
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D003546:Cysteine Endopeptidases / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry; D030041:Hepatitis A virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000097:blood; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D044967:Serum / Q000821:virology; D013785:Thailand; D014764:Viral Proteins / Q000235:genetics; D015678:Viral Structural Proteins / Q000235:genetics
chemical_list: D000914:Antibodies, Viral; D018076:DNA, Complementary; D012367:RNA, Viral; C096539:VP1 protein, hepatitis A virus; D014764:Viral Proteins; D015678:Viral Structural Proteins; D003546:Cysteine Endopeptidases; C057400:picornain 2A, Picornavirus