Hepatitis C virus genotype 5: epidemiological characteristics and sensitivity to combination therapy with interferon-alpha plus ribavirin.

Twenty-six patients living in the Midi-Pyrenees region of France who were infected with hepatitis C virus (HCV) genotype 5 were investigated. Most of these patients were of advanced age and had been infected nosocomially or by blood transfusion. Our case-control study, in which we treated patients with interferon- alpha plus ribavirin, indicated that, 24 weeks after the beginning of treatment, the virus response in patients infected with HCV genotype 5 was better than that in patients infected with HCV genotype 1 (100% of patients negative for detectable HCV RNA vs. 36.3%, respectively; P < .01); furthermore, 48 weeks after the end of treatment, the virus response in patients infected with HCV genotype 5 was better than that in patients infected with HCV genotype 1 (63.6% vs. 22.7%, respectively; P < .05) and was similar to that in patients infected with HCV genotype 2 or 3 (66.6%). These results show that HCV genotype 5 might have good intrinsic sensitivity to combination therapy with interferon- alpha plus ribavirin.