Molecular evolutionary analyses implicate injection treatment for schistosomiasis in the initial hepatitis C epidemics in Japan

Yasuhito Tanaka, Kousuke Hanada, Etsuro Orito, Yoshihiro Akahane, Kazuaki Chayama, Hiroshi Yoshizawa, Michio Sata, Nobuo Ohta, Yuzo Miyakawa, Takashi Gojobori, Masashi Mizokami

Research output: Contribution to journalArticlepeer-review

39 Scopus citations


The mortality due to hepatocellular carcinoma (HCC) has ranged widely in various areas of Japan since 30 years ago and the incidence was particularly high in once Schistosoma japonicum (Sj)-endemic areas. Our aim was to estimate the spread time of hepatitis C virus (HCV) infection in the past with possible relevance to a higher incidence of HCC in once Sj-endemic than Sj-nonendemic areas. During 2001, 131 strains of HCV-1b were obtained from patients in three previously Sj-endemic areas, as well as Sj-nonendemic areas in Japan and a cross-sectional study was conducted on them with molecular evolutionary analyses. A phylogenetic tree reconstructed on HCV-1b sequences in the NS5B region disclosed 2 independent clusters for Sj-positive and -negative groups with a high bootstrap value. The estimated effective number of HCV-infections indicated a transition from quiescence to rapid exponential growth in the 1920s among patients with schistosomiasis, which is 20 years earlier than that among patients without schistosomiasis. The estimated spread time in previously Sj-endemic areas in Japan coincides with injection treatment for Sj since 1921. A high incidence of HCC there would be attributed to a long duration of HCV infection since 1920s.

Original languageEnglish (US)
Pages (from-to)47-53
Number of pages7
JournalJournal of Hepatology
Issue number1
StatePublished - Jan 2005
Externally publishedYes

Bibliographical note

Funding Information:
We greatly appreciate Dr Oliver G. Pybus (Department of Zoology, University of Oxford, Oxford, UK) for his enlightening advice on molecular evolutionary analyses using Genie v3.5. We thank Ms Yoshiko Kobayashi (Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan) for technical assistance and Dr Tatsuya Ide (Kurume University School of Medicine, Fukuoka, Japan) and Dr Hirotaka Kono (Hiroshima University Graduate School of Biomedical Sciences, School of Medicine, Hiroshima, Japan) for providing us with valuable materials. The work was supported by a grant-in-aid from the Ministry of Health, Labour and Welfare of Japan (H13-kanen-2), grants-in-aid for Young Scientists (A) from the Ministry of Education, Culture, Science and Sports of Japan (16689016), The Hori Information Science Promotion Foundation and Miyakawa Memorial Research Foundation.


  • Hepatitis C virus
  • Hepatocellular carcinoma
  • Molecular evolutionary analysis
  • Schistosoma japonicum

ASJC Scopus subject areas

  • Hepatology


Dive into the research topics of 'Molecular evolutionary analyses implicate injection treatment for schistosomiasis in the initial hepatitis C epidemics in Japan'. Together they form a unique fingerprint.

Cite this