Changing HCV genotypes distribution in Poland--relation to source and time of infection.

BACKGROUND: Understanding the distribution of HCV genotypes has implications for prognosis and therapy of hepatitis C. OBJECTIVES: To describe the distribution of HCV genotypes in Poland in relation to route of transmission and year of infection. STUDY DESIGN: Patients with chronic liver disease were evaluated at the Department of Infectious Diseases, Bialystok (Poland). HCV genotype was determined by means of 5'UTR sequencing and comparison with known sequences of particular genotypes. RESULTS: The genotypes mostly frequently detected were genotype 1 (57.5%); genotype 3 (31.3%); and genotype 4 (8.4%). Genotype 1 constituted the majority of HCV infections caused by blood transfusion (68.8%) and only 34.8% of HCV infections in the intravenous drug use (IVDU) group (p<0.05). In contrast genotype 3 constituted the majority of HCV infections in the IVDU group (56.5%). We observed a significant increase in the proportion of genotype 3 infections detected after 2000--from 19.1% to 38.9%. CONCLUSIONS: The relative proportion of genotype 1b in Poland has decreased and that of genotype 3a has increased, especially among IVDU.