Change in hepatitis C virus genotype in injecting drug users

• Published in: Journal of medical virology 2004-12, Vol.74 (4), p.543-545
• Main Authors: Aitken, Campbell, McCaw, Rhonda, Jardine, Darren, Bowden, Scott, Higgs, Peter, Nguyen, Oanh, Crofts, Nick, Hellard, Margaret
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Epidemiology; Fundamental and applied biological sciences. Psychology; Genotype; genotype variability; HCV incidence; Hepacivirus - classification; Hepacivirus - genetics; Hepacivirus - immunology; Hepatitis C - epidemiology; Hepatitis C - etiology; Hepatitis C - virology; Human viral diseases; illicit drug users; infection dynamics; Infectious diseases; Medical sciences; Microbiology; Miscellaneous; Substance Abuse, Intravenous - complications; Substance Abuse, Intravenous - virology; Viral diseases; Virology
• ISSN: 0146-6615; 1096-9071
• DOI: 10.1002/jmv.20212

Six major genotypes of the hepatitis C virus (HCV) have been described; it is assumed to be uncommon for genotypes to change in chronically infected individuals. Venous blood samples obtained from Vietnamese‐Australian injecting drug users who participated in successive studies conducted in Melbourne, Australia, were genotyped using the Bayer line probe assay and genotype confirmed by sequencing whenever possible. Three changes of HCV genotype were observed, and one infection in an individual not exposed previously. The rate of change of genotype was 3 in 11.4 person‐years (py), or 26.4 per 100 py (95% CI: 8.5, 81.6). Traditionally‐calculated HCV incidence was 1 in 4.3 py, or 23.3 per 100 py (95% CI: 3.3, 165.1). These data imply that HCV genotype change in injecting drug users occurs at least as frequently as infections in naïve individuals, and that traditionally‐calculated HCV incidence rates represent a minority of actual HCV transmission among practicing injecting drug users. J. Med. Virol. 74:543–545, 2004. © 2004 Wiley‐Liss, Inc.