title: Multiple routes of hepatitis C virus transmission among injection drug users in Hai Phong, Northern Vietnam.
abstract: To identify hepatitis C virus (HCV) transmission routes among injection drug users in Northern Vietnam, plasma samples were collected from 486 drug users in Hai Phong. Plasma viral RNA was extracted from 323 (66.5%) samples that were positive for anti-HCV antibodies. Portions of the HCV 5'-untranslated (5'UTR)-Core and NS5B genes were amplified by reverse-transcriptase polymerase chain reaction, sequenced directly, and genotyped in 194 and 195 specimens, respectively. Both regions were genotyped in 137 specimens. In the 5'UTR-Core region, genotype 6a was predominant (32.5%), followed by genotype 1a (23.7%), genotype 1b (20.6%), and genotype 6e (14.4%). In the NS5B region, genotype 1a was predominant (42.6%), followed by genotype 1b (24.1%), genotype 6a (14.4%), genotype 3b (7.2%), and genotype 6e (5.1%). Of the 137 specimens with both regions genotyped, 23 (16.8%) showed discordant genotyping results between the two regions, suggesting possible recombination and/or dual infection. Phylogenetic analysis revealed close associations between Hai Phong strains and strains from Southern China: the Yunnan province for genotype 3b; the Guangxi province for genotype 6e; the USA for genotype 1a; and Southern Vietnam for genotypes 1a and 6e. The human immunodeficiency virus (HIV) infection rate among HCV-infected injection drug users was 52.6-55.4% and did not differ significantly by HCV genotype. Most drug users infected with HIV-1 [98.8% (171/173)] were co-infected with HCV. These results suggest multiple routes of HCV transmission among injection drug users in Northern Vietnam that may also be HIV transmission routes.
authors.affiliation: Department of Viral Infection and International Health, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Tanimoto
authors.forename: Hung Cuong
authors.initials: HC
authors.lastname: Nguyen
authors.forename: Azumi
authors.initials: A
authors.lastname: Ishizaki
authors.forename: Phan Thi Thu
authors.initials: PT
authors.lastname: Chung
authors.forename: Thi Thanh Huyen
authors.initials: TT
authors.lastname: Hoang
authors.forename: Vu Trung
authors.initials: VT
authors.lastname: Nguyen
authors.forename: Seiji
authors.initials: S
authors.lastname: Kageyama
authors.forename: Shinichi
authors.initials: S
authors.lastname: Oka
authors.forename: Van Thuc
authors.initials: VT
authors.lastname: Pham
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ichimura
mesh_terms: D020121:5' Untranslated Regions; D000328:Adult; D000368:Aged; D016000:Cluster Analysis; D015897:Comorbidity; D055030:Drug Users; D005838:Genotype; D015658:HIV Infections / Q000453:epidemiology; D016174:Hepacivirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006526:Hepatitis C / Q000453:epidemiology* / Q000635:transmission*; D006801:Humans; D007275:Injections, Intravenous / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D015995:Prevalence; D012367:RNA, Viral / Q000097:blood / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D015819:Substance Abuse, Intravenous / Q000150:complications*; D014744:Vietnam / Q000453:epidemiology; D014758:Viral Core Proteins / Q000235:genetics; D017361:Viral Nonstructural Proteins / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase
chemical_list: D020121:5' Untranslated Regions; D012367:RNA, Viral; D014758:Viral Core Proteins; D017361:Viral Nonstructural Proteins; C069130:nucleocapsid protein, Hepatitis C virus; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase