Changing prevalence of hepatitis C virus genotypes: Molecular epidemiology and clinical implications in the hepatitis C virus hyperendemic areas and a tertiary referral center in Taiwan

Yu, Ming‐Lung; Chuang, Wan‐Long; Chen, Shinn‐Cherng; Dai, Chia‐Yen; Hou, Cheng; Wang, Jing‐Houng; Lu, Sheng–Nan; Huang, Jee‐Fu; Lin, Zu‐Yau; Hsieh, Ming‐Yuh; Tsai, Jung‐Fa; Wang, Liang‐Yen; Chang, Wen‐Yu

doi:10.1002/jmv.2001.abs

Cited by 34 publications

(57 citation statements)

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“…The similar epidemiological situation was also described in other former Soviet Union Republics, and most Asian countries, such as Moldova, Russia, Belarus, Mongolia [Lvov et al, 1996;Viazov et al, 1997]; Taiwan [Yu et al, 2001]; China ; and Japan [Noguchi et al, 1997], where genotype 1b is also common. Genotype 3a found in 25.0% of all cases typed was second most common type in the country.…”

Section: Discussionsupporting

confidence: 61%

Hepatitis C virus molecular epidemiology in Uzbekistan

Kurbanov

Tanaka

Sugauchi

et al. 2003

Journal of Medical Virology

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The aim of this study was to identify hepatitis C virus (HCV) genotypes and to estimate their prevalence in various risk groups and the regional distribution in Uzbekistan. Preliminary serological screening of 1,269 subjects revealed 6.5% anti-HCV-positive in a general population, 27.1% in patient groups, and 51.7% among intravenous drug users. HCV genotypes of 104 anti-HCV-positive subjects were determined using a PCR-genotyping system in core region, and the results were supported by nucleotide sequencing of the NS5B region. Genotype 1b identified in total 64.2%, was the most prevalent. The genotype 3a identified in 25.0% was the second one distributed. HCV genotypes 2a, 1a, 2b, and 3b were identified in 3.8%, 2.9%, 2.9%, and 1.0% of cases, respectively. The intravenous drug users were distinguished from other groups by having the highest prevalence of genotype 3a, i.e., 50.0%, higher than the 33.3% for genotype 1b in this group. Geographically, genotype 1b was common; genotype 3a was also found frequently in all three regions. Uncommon HCV genotypes (1a, 2a, 2b, and 3b) were found in comparatively greater variability in the western region. Molecular evolutionary analysis based on the NS5B region did not reveal specific clustering or indigenous strains among Uzbekistan HCV isolates. In summary, two main mechanisms of HCV infection distribution were observed in Uzbekistan: HCV 1b genotype infection is widespread through blood products, and HCV 3a genotype infection is spreading through the growing number of intravenous drug users.

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Section: Discussionsupporting

confidence: 61%

Hepatitis C virus molecular epidemiology in Uzbekistan

Kurbanov

Tanaka

Sugauchi

et al. 2003

Journal of Medical Virology

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“…In previous studies utilizing reverse transcription polymerase chain reaction (RT-PCR) with type-specifi c primers [26][27][28] , 58-73% of HCV isolates from northern Taiwan were found to be genotype 1b and 7.4-16.5% genotype 2a [27][28][29] , while around 48-64.3% were genotype 1b and 35-41% genotype 2a in southern Taiwan [27,30] .…”

Section: Prevalence Of Hcv Genotypes and Their Infl Uence On The Progmentioning

confidence: 99%

Viral Etiology of Hepatocellular Carcinoma and HCV Genotypes in Taiwan

Lee

Hung²,

Lu³

et al. 2005

Intervirology

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Etiologic variations of hepatocellular carcinoma (HCC) exist in different geographic areas of the world. Hepatitis B virus infection is associated with HCC. However, hepatitis C virus (HCV) infection plays an increasingly more important role in the development of HCC and is associated with more than 30% of HCC in Taiwan. The prevalence of HCV infection and HCV genotypes vary in different geographic areas. The prevalence of HCV genotype 1b (HCV-1b) was around 50–70% in Taiwan and even varied in different townships. In addition to host factors, HCV genotypes may be associated with the development of HCC. In our study, the prevalence of HCV-1b in patients with HCC was significantly higher than in those with liver cirrhosis and chronic hepatitis; multivariate analysis revealed that the disease severity was significantly correlated with age and HCV-1b. Furthermore, HCV-1b was associated with a lower response rate to interferon (IFN) therapy than HCV-2. Our study has demonstrated that mutations in the IFN sensitivity-determining region, spanning nucleotides 2,209–2,248 in the NS5A region, correlate with the sustained virological response to combination therapy with IFN and ribavirin in patients with chronic HCV-1b infection in Taiwan. A third-generation enzyme immunoassay for antibody to HCV can be used to predict viremia and monitor the virological response.

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“…Our study suggested that independent HCV outbreaks continue in hyperendemic areas in Taiwan, and that the HCV infection keeps changing along with the relative prevalence of HCV genotypes in relation to age. Both the correlation of genotype 1b with age (cohort effect) and intrinsic properties of HCV genotypes are probably responsible for the association between genotype and pathogenesis of HCV infection [29] .…”

Section: Distribution Of Hcv Genotypes In Southern Taiwanmentioning

confidence: 99%

“…In addition, several areas hyperendemic for HCV have been discovered in southern Taiwan [16][17][18][19] ; the molecular epidemiology of HCV may differ in these areas. In 1,164 subjects positive for anti-HCV and HCV RNA in serum from three HCV hyperendemic areas (community-based; Masago, Tzukuan and Taoyuan) and a tertiary referral center (hospitalbased) in southern Taiwan, we determined genotype distribution to evaluate the age-specifi c prevalence of HCV genotypes and clarify the relationship between genotype and pathogenesis of HCV infection [29] ; HCV genotypes were examined by the method of Okamoto et al [30] . HCV genotypes were able to be determined in 1,100 of 1,164 (94.5%) subjects.…”

Section: Distribution Of Hcv Genotypes In Southern Taiwanmentioning

confidence: 99%

Treatment of Chronic Hepatitis C in Southern Taiwan

Chuang

et al. 2005

Intervirology

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Chronic hepatitis C virus (HCV) infection may lead to cirrhosis and hepatocellular carcinoma. Interferon (IFN)-α is effective in the treatment of chronic hepatitis C. The rate of response to IFN is enhanced by increasing the IFN dose. Extending the treatment duration can reduce the relapse rate. Addition of ribavirin to IFN increases the sustained virological response (SVR). Thus, combination therapy with IFN and ribavirin was adopted for the treatment of chronic hepatitis C in Kaohsiung Medical University Hospital in 1998. Approximately 60% of patients receiving IFN/ribavirin therapy gained SVR. IFN 6 million units three times per week combined with daily ribavirin for 6 months achieved SVR more frequently than combination therapy with 3 million units. Factors for SVR in these combination regimens were HCV genotype, viral load and early virological response. Long-term follow-up of patients treated with IFN has shown that SVR might reduce the risk of progression to cirrhosis and hepatocellular carcinoma. Pegylated (peg)-IFN has a longer half-life and better efficacy. Combination therapy with peg-IFN and ribavirin accomplished higher SVR than conventional IFN and ribavirin. A multicenter clinical trial was conducted in Taiwan to compare the efficacy of combination therapy between peg-IFN/ribavirin and conventional IFN/ribavirin for 6 months. SVR was higher in patients receiving peg-IFN and ribavirin, especially in those infected with HCV genotype 1b. Based on the results obtained, the national health insurance started to sponsor the combination therapy in October 2003, with a suggested duration for 6 months. Some small-scale studies in Taiwan have postulated higher SVR for treatment duration of 12 than of 6 months in patients with genotype 1b. Further investigation should be conducted in the near future.

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Changing prevalence of hepatitis C virus genotypes: Molecular epidemiology and clinical implications in the hepatitis C virus hyperendemic areas and a tertiary referral center in Taiwan

Cited by 34 publications

References 0 publications

Hepatitis C virus molecular epidemiology in Uzbekistan

Hepatitis C virus molecular epidemiology in Uzbekistan

Viral Etiology of Hepatocellular Carcinoma and HCV Genotypes in Taiwan

Treatment of Chronic Hepatitis C in Southern Taiwan

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