Epidemiology of Chronic Hepatitis C Virus Infection in High Risk Groups

Background and Aims: The relative frequency of hepatitis C virus (HCY) genotypes and differences of HCY genotype distribution in relation to transmission mode, age and acquisition time of infection were investigated among 758 highrisk patients: 118 were under dialysis (OP), 109 intravenous drug users (IOU), 317 hepatologic (HP) and 214 ~thalassemic patients (~TM). Methods: A total of 478 anti-HeY (Enzyme Immunoassay EIA) positive sera were further examined for HCY-RNA (Transcription Mediated Assay-TMA), HCY genotype (Line Probe Assay-LiPA) and hepatitis C viral load (branched ONAbONA). With the exception of IOU group, patients were contaminated before 1990 after blood transfusion or other nosocomial treatment. For IOU, who were significantly younger individuals than OP and HP, HCY infection occurred the last decade after IY drug use. Results: The overall distribution of HCY genotypes 1, 2, 3 and 4 was 38.6%, 8.4%, 40.7%, and 12.4%, respectively. With the exception of IOU group in which genotype 3 was by far the most common, genotype 1 predominated in all patients examined. Conclusions: Results reveal a difference of HCY genotype distribution among patients of high risk groups in our area, as a sequel of epidemiologic changes in HCY transmission. IOU 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.