PREVALENCE OF HEPATITIS-C VIRUS GENOTYPES IN SPANISH DRUG-ADDICTS WITH CHRONIC HEPATITIS-C

The hepatitis C virus (HCV) shows a wide genetic variability. The diff erent variants of HCV have been classified into 9 types and different subtypes. Some genotypes have a characteristic geographic distribution and seem to be associated with precise ways of contagion. Serum sampl es from 107 spanish patients with chronic hepatitis C were studied, wh ich were distributed as follows: 88 parenteral drug addicts (PDA) and a control group of 19 subjects made up by 4 transfused, 5 probably sex ually infected and 10 with unknown contagion source (sporadic cases). HCV typing was made by means of the PCR method and later hybridization analysis with complementary probes of different types and subtypes of HCV exposed on a smooth surface (Inno-LiPA). A total of 105 (98.4%) p atients had their viruses genotyped. There was more than one genotype in the same subject (co-infection) in 43.8% of cases and co-infection 1a + 1b was the most common (82.7%). While not reaching a statistic si gnificance, co-infections were more frequent in PDA (47.1%) than in th e remaining patients (27.8%). In the infected patients with only one g enotype, the most common genotype was 1a, both in PDA (22.9%) and in s ubjects with transfusional HCV, sexual or sporadic (38.9%). In decreas ing frequency came genotypes 1b (13.3%) and 3a (11.4%). Other genotype s were very uncommon (2a and 4) or were absent (2b and 5) as unique in fections. In conclusion, genotypes non-1b of HCV, mainly 1a and to a l esser extent 3a, are the most common in a spanish population made up m ainly by young persons with risk antecedents for HIV infection, partic ularly PDA. Furthermore, co-infection with HCV genotypes is frequent i n this population.