Seroprevalence and genotype of hepatitis C virus among immigrant workers from Cambodia and Myanmar in Thailand.

OBJECTIVE There is a large number of immigrant workers from Cambodia and Myanmar in Thailand. The aim of our study was to determine seroprevalence and genotypes of hepatitis C virus (HCV) in this group. METHODS Immigrants aged between 15 and 60 years (1,431 Cambodians and 1,594 Myanmarese) were recruited into this study. Each sample was screened for anti-HCV by ELISA. RNA was extracted from seropositive samples and RT-PCR was performed in order to amplify the HCV core region. Each sample was subsequently sequenced, and the genotype was determined by phylogenetic analysis. RESULTS The prevalence of HCV infection in immigrant workers from Cambodia and Myanmar was 33 (2.3%) and 27 (1.69%) samples, respectively. Of the anti-HCV-positive individuals, 25 (75.8%) from Cambodia and 15 (55.6%) from Myanmar harbored viral RNA. Phylogenetic analysis showed that the predominant HCV genotypes in this group were 1a, 1b, 3a, 3b and 6 (6e, 6f, 6m, 6p and 6r). Most HCV isolates can be found in Thailand, though some subtypes of HCV-6 are uncommon. CONCLUSIONS This study shows the HCV seroprevalence and genotypes among immigrant Cambodians and Myanmarese which may reflect the prevalence in each country and closely relate to the prevalence in the guest country.