[Distribution of the genotypes of hepatitis C virus in intravenous drug addicts in Argentina].

Intravenous drug addiction (IVD) is an unfrequent risk factor in Argentina, representing less than 10% of patients (pts) with chronic HCV infection seen in our Unit. In order to study the genotypes (Gt) in IVD and compare them with a non drug addicted control population, 68 pts with a history of IVD were enrolled in this study and compared with 68 non drug addict (NDA) pts with chronic HCV, with similar age and gender distribution. In all pts a liver biopsy was performed. Genotyping was done by INNO LiPA (Innogenetics, Belgium). Mean age in both groups was 35 +/- 7.8 years and 50 were males. No difference was observed between both groups in the prevalence of Gt1a, Gt2a/c and in those with mixed infections. The prevalence of Gt1b in IVD was 19.1% and in NDA 38.2% (p = 0.0228). A highly significant difference was also observed in the prevalence of Gt3a, of 42.6% in IVD and only 11.8% in NDA (p = 0.0001). Gt1a was the second most frequent genotype in IVD pts (26.5%). Simultaneous HIV infection was present in 8 IVD pts (11.8%) and in none of NDA group. Liver biopsies showed a higher prevalence of mild chronic hepatitis in NDA (57.3%) than in IVD (32.4%) (p = 0.0058). Severe chronic hepatitis with advanced fibrosis or cirrhosis was more frequent in the Gt3 of the group with IVD when compared with Gt3 of the NDA group. It can be concluded that in accordance with other geographical areas, Gt3a is far more prevalent in intravenous drugs addicts than in the general population in Argentina where Gt1b is more frequent. Mild forms of chronic hepatitis are less frequent in IVD. In spite of the relatively small group with HCV co-infection with HIV, it seems important to note that 2/8 (25%) showed severe hepatitis C or cirrhosis.