Department of Medicine, Stanford University Medical Center, Palo Alto, CA, USA.
The global burden of hepatitis C (HCV) infection is mostly found in Africa, the Middle East and Asia, where HCV genotypes 4, 5 and 6 are common. The literature on these genotypes is sparse and this synopsis will review characteristics of patients infected with these genotypes.
To review characteristics of patients infected with HCV genotypes 4, 5 and 6.
PubMed search for 'hepatitis C' AND 'genotype 4', 'hepatitis C' AND 'genotype 5', and 'hepatitis C' AND 'genotype 6' was conducted and relevant articles were reviewed.
Intravenous drug use is generally responsible for HCV genotype 4 infection in developed countries, but unsafe medical practices cause most cases of HCV genotypes 4, 5 and 6 in endemic countries. The sustained virological response (SVR) rate for patients with HCV genotype 4 who receive pegylated interferon and ribavirin for 48 weeks ranges from 40% to 70% in various small studies. The SVR rate is in the 60-70% range for HCV genotype 5 and 70-80% range for HCV genotype 6 following 48 weeks with pegylated interferon and ribavirin. Preliminary data suggest that a shorter course of 24 weeks of pegylated interferon and ribavirin may be acceptable for HCV genotype 6, with an SVR rate of approximately 70%.
The current standard-of-care therapy for HCV genotypes 4, 5 and 6 is pegylated interferon and ribavirin for 48 weeks. A shorter course with 24 weeks of therapy may be considered for patients with genotype 6. Newer and much more effective therapies may be forthcoming in the next few years.