Multiple routes of hepatitis C virus transmission among injection drug users in Hai Phong, Northern Vietnam

• Published in: Journal of medical virology 2010-08, Vol.82 (8), p.1355-1363
• Main Authors: Tanimoto, Tomoaki, Cuong, Nguyen Hung, Ishizaki, Azumi, Chung, Phan Thi Thu, Huyen, Hoang Thi Thanh, Trung, Nguyen Vu, Kageyama, Seiji, Oka, Shinichi, Thuc, Pham Van, Ichimura, Hiroshi
• Format: Article
• Language: English
• Subjects: 5' Untranslated Regions; Adult; Aged; Cluster Analysis; Comorbidity; Drug Users; Genotype; Hepacivirus - classification; Hepacivirus - genetics; Hepacivirus - isolation & purification; Hepatitis C - epidemiology; Hepatitis C - transmission; HIV; HIV Infections - epidemiology; Humans; Injections, Intravenous - adverse effects; Male; Middle Aged; Molecular Epidemiology; Molecular Sequence Data; Prevalence; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral - blood; RNA, Viral - genetics; RNA, Viral - isolation & purification; Sequence Analysis, DNA; Sequence Homology; Southeast Asia; Substance Abuse, Intravenous - complications; Vietnam - epidemiology; Viral Core Proteins - genetics; Viral Nonstructural Proteins - genetics
• ISSN: 0146-6615; 1096-9071
• DOI: 10.1002/jmv.21787

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. J. Med. Virol. 82:1355-1363, 2010.