title: Molecular epidemiological study of hepatitis B virus among migrant workers from Cambodia, Laos, and Myanmar to Thailand.
abstract: Although hepatitis B virus (HBV) infection is endemic in Southeast Asia, molecular epidemiological data on HBV circulating in some countries are limited. The aims of this study were to evaluate the seroprevalence of HBV and its genetic variability among migrant workers from Cambodia, Laos, and Myanmar in Thailand. Sera collected from 1,119 Cambodian, 787 Laotian, and 1,103 Myanmarese workers were tested for HBsAg. HBV DNA was amplified and the pre-S/S region was sequenced for genotyping and genetic mutation analysis. HBsAg was detected in 282 (9.4%). The prevalence of HBsAg among migrant workers from Cambodia, Laos, and Myanmar was 10.8%, 6.9%, and 9.7%, respectively. Of 224 subjects positive for HBV DNA, 86% were classified as genotype C (99% were sub-genotype C1) and 11.6% were genotype B (30.8%, 34.6%, and 30.8% were sub-genotypes B2, B3, and B4, respectively). Various point mutations in the "a" determinant region were detected in approximately 18% of these samples, of which Ile126Ser/Asn was the most frequent variant. Sequencing analysis showed that 19.1% of samples had pre-S mutations, with pre-S2 deletion as the most common mutant (7.7%) followed by pre-S2 start codon mutation (3.8%) and both pre-S2 deletion and start codon mutation (3.3%). High prevalence of HBV infection (approximately 7-11%) was found among migrant workers from Cambodia, Laos, and Myanmar, which may reflect the current seroprevalence in their respective countries. The data also demonstrated that HBV sub-genotype C1 was the predominant strain and various mutations of HBV occurring naturally were not uncommon among these populations.
authors.affiliation: Center of Excellence in Clinical Virology, Faculty of Medicine, Department of Pediatrics, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Pattaratida
authors.initials: P
authors.lastname: Sa-Nguanmoo
authors.forename: Pisit
authors.initials: P
authors.lastname: Tangkijvanich
authors.forename: Nutchanart
authors.initials: N
authors.lastname: Thawornsuk
authors.forename: Preeyaporn
authors.initials: P
authors.lastname: Vichaiwattana
authors.forename: Kesmanee
authors.initials: K
authors.lastname: Prianantathavorn
authors.forename: Apiradee
authors.initials: A
authors.lastname: Theamboonlers
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Yong
authors.initials: Y
authors.lastname: Poovorawan
mesh_terms: D000293:Adolescent; D000328:Adult; D019943:Amino Acid Substitution / Q000235:genetics; D002160:Cambodia; D016000:Cluster Analysis; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D005260:Female; D005838:Genotype; D006509:Hepatitis B / Q000453:epidemiology* / Q000821:virology; D006514:Hepatitis B Surface Antigens / Q000097:blood* / Q000235:genetics; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007812:Laos; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D002052:Myanmar; D017354:Point Mutation; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D017385:Sequence Homology; D016036:Seroepidemiologic Studies; D013785:Thailand / Q000453:epidemiology; D055815:Young Adult
chemical_list: D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens