Epidemiology of chronic hepatitis C virus infection in high risk groups

Background and Aims: The relative frequency of hepatitis C virus (HCV) genotypes and differences of HCV genotype distribution in relation to transmission mode, age and acquisition time of infection were investigated among 758 high-risk patients: 118 were under dialysis (DP), 109 intravenous drug users (IDU), 317 hepatologic (HP) and 2,14 thalassemic patients (beta TM). Methods: A total of 478 anti-KCV (Enzyme Immunoassay EIA) positive sera were further examined for HCV-RNA (Transcription Mediated Assay-TMA), HCV genotype (Line Probe Assay-LiPA) and hepatitis C viral load (branched DNA-bDNA). With the exception of IDU group, patients were contaminated before 1990 after blood transfusion or other nosocomial treatment. For IDU, who were significantly younger individuals than DP and HP, HCV infection occurred the last decade after IV drug use. Results: The overall distribution of HCV genotypes 1, 2, 3 and 4 was 38.6%, 8.4%, 40.7%, and 12.4%, respectively. With the exception of IDU group in which genotype 3 was by far the most common, genotype 1 predominated in all patients examined. Conclusions: Results reveal a difference of HCV genotype distribution among patients of high risk groups in our area, as a sequel of epidemiologic changes in HCV transmission. IDU group may be also responsible for a new hepatitis C epidemic and may constitute the new significant reservoir in the future. This transition may require new prevention protocols and therapeutic strategies.