The prevalence of hepatitis C virus (HCV) in Asia is 0.5% to 4.7%, with three different genotypes predominating, depending on the geographic region: genotype 1b in East Asia, genotype 3 in South and Southeast Asia, and genotype 6 in Indochina. Official approval for direct-acting antiviral agents (DAAs) in Asia lags significantly behind that in the West, such that in most countries the mainstay of therapy is still pegylated interferon and ribavirin (PR). Because the interleukin-28B genetic variant, associated with a high sustained virologic response (SVR), is common in Asians, this treatment is still acceptable in Asian patients with HCV infections. A roadmap for HCV therapy that starts with PR and takes into account those DAAs already approved in some Asian countries can provide guidance as to the best strategies for management, particularly of genotype 1 and 3 infections, based on SVR rates. Sofosbuvir and PR are likely to be the initial therapies for genotype 1 and 3 disease, although in the former these drugs may be suboptimal in patients with cirrhosis (62% SVR) and the extension of treatment to 24 weeks may be required. For difficult to treat genotype 3 infections in treatment-experienced patients with cirrhosis, a combination of sofosbuvir and PR result in an 83% SVR and is, therefore, currently the optimal treatment regimen. Treatment failure is best avoided since data on rescue therapies for DAA failure are still incomplete.
Antiviral Agents/adverse effects/*therapeutic use ; Asia/epidemiology ; Drug Therapy, Combination ; Genotype ; Hepacivirus/*drug effects/genetics ; Hepatitis C/diagnosis/*drug therapy/epidemiology/genetics ; Humans ; Interleukins/genetics ; National Health Programs ; Practice Guidelines as Topic ; Prevalence ; Time Factors ; Treatment Outcome

BACKGROUND/AIMS: Hepatitis C genotypes 1 and 2 are widely distributed globally. In contrast, genotype 6 is found mainly in Southeast Asia, while genotype 6 is rare in Korea. This study aims to investigate the prevalence, risk factors and clinical characteristics of patients with genotype 6 chronic hepatitis C. METHODS: We retrospectively identified 133 HCV-infected patients who underwent HCV genotype analysis between January 2012 and December 2012, and analyzed the prevalence, risk factors and clinical characteristics of patients diagnosed with genotype 6 chronic hepatitis C. RESULTS: Among 133 patients, 53 patients (39.8%) were infected with genotype 1, 62 patients (46.6%) with genotype 2, 2 patients (1.5%) with genotype 3, 14 patients (10.5%) with genotype 6, and 2 patients (1.5%) with mixed genotypes (genotype 1 and 6). The risk factors associated with genotype 6 were acupuncture (n=4, 28.6%), intravenous drug use (n=3, 21.4%), tattoo (n=2, 14.3%), and transfusion (n=2, 14.3%). Of the 14 patients with genotype 6, 6 patients were treated with pegylated interferon and ribavirin. Five patients had reached the end of treatment. All patients reaching end of treatment for genotype 6 showed early virological response and sustained virological response. CONCLUSIONS: The prevalence of genotype 6 is 10.5% and mixed infections of genotype 1 and 6 are 1.5% in patients with chronic hepatitis C. A major potential risk factor is intravenous drug use and the treatment response rate to pegylated interferon plus ribavirin is high in patients with genotype 6 chronic hepatitis C. Large scale multicenter studies are needed.
Acupuncture Therapy ; Adult ; Aged ; Antiviral Agents/therapeutic use ; Blood Transfusion ; Drug Therapy, Combination ; Female ; Genotype ; Hepacivirus/*genetics/isolation & purification ; Hepatitis C, Chronic/*diagnosis/drug therapy/epidemiology ; Humans ; Interferon-alpha/therapeutic use ; Male ; Middle Aged ; Polyethylene Glycols/therapeutic use ; Prevalence ; RNA, Viral/genetics ; Recombinant Proteins/therapeutic use ; Republic of Korea ; Retrospective Studies ; Ribavirin/therapeutic use ; Risk Factors ; Tattooing

BACKGROUND/AIMS: The distribution of hepatitis C virus (HCV) genotypes varies geographically. In Korea, genotypes 1 and 2 comprise more than 90% of HCV infections, while genotype 6 is very rare. This study compared the clinical and epidemiological characteristics of patients with genotype 6 HCV infection with those infected with HCV genotypes 1 and 2. METHODS: This was a prospective, multicenter HCV cohort study that enrolled 1,173 adult patients, of which 930 underwent HCV genotype analysis, and only 9 (1.0%) were found to be infected with genotype 6 HCV. The clinical and epidemiological parameters of the genotypes were compared. RESULTS: The patients with genotype 6 HCV had a mean age of 41.5 years, 77.8% were male, and they had no distinct laboratory features. A sustained virologic response (SVR) was observed in four (67%) of six patients who received antiviral therapy. Risk factors such as the presence of a tattoo (n=6, 66.7%), more than three sexual partners (n=3, 33.3%), and injection drug use (n=3, 33.3%) were more common among genotype 6 patients than among genotypes 1 or 2. CONCLUSIONS: The epidemiology and treatment response of patients infected with genotype 6 HCV differed significantly from those with genotypes 1 or 2, warranting continuous monitoring.
Adult ; Antiviral Agents/therapeutic use ; Asian Continental Ancestry Group ; Cohort Studies ; Female ; Genotype ; Hepacivirus/*genetics ; Hepatitis C, Chronic/*diagnosis/drug therapy/epidemiology ; Humans ; Liver/pathology ; Male ; Middle Aged ; Prospective Studies ; RNA, Viral/blood ; Republic of Korea ; Risk Factors ; Sexual Behavior ; Substance-Related Disorders/complications ; Tattooing