Journal of Gastroenterology

, Volume 41, Issue 10, pp 981–986

Molecular epidemiology of hepatitis A virus in metropolitan areas in Japan

  • Hideaki Takahashi
  • Hiroshi Yotsuyanagi
  • Kiyomi Yasuda
  • Tomohiko Koibuchi
  • Michihiro Suzuki
  • Tomohiro Kato
  • Tetsuya Nakamura
  • Aikichi Iwamoto
  • Kusuki Nishioka
  • Shiro Iino
  • Kazuhiko Koike
  • Fumio Itoh
Article

DOI: 10.1007/s00535-006-1888-9

Cite this article as:
Takahashi, H., Yotsuyanagi, H., Yasuda, K. et al. J Gastroenterol (2006) 41: 981. doi:10.1007/s00535-006-1888-9

Abstract

Background

Transmission routes of hepatitis A virus (HAV) in Japan have changed. The present study investigated changes of transmission routes in relation to genetic drift.

Methods

All 60 patients who were admitted between 1993 and 2003 with a diagnosis of hepatitis A were retrospectively analyzed. Nucleotide sequences of the VP1/2A region of the HAV recovered from their sera were determined.

Results

The suspected transmission routes were household contact, 19 (31%); food or waterborne, 16 (27%); homosexual activity, 11 (18%); international travel, 4 (7%); and unknown 10. (17%). The 11 patients presumably infected through homosexual activity were found exclusively in 1998 and 1999. The proportion of patients exposed through homosexual behavior and household contact was higher in those 2 years than in other years. Nucleotide sequences could be determined for 58 patients. Fifty-seven of the 58 sequences belonged to genotype IA HAV, with less than 10% nucleotide diversity. Of the 27 sequences isolated during 1998 and 1999, 25 had an identical nucleotide sequence regardless of the suspected transmission route. In contrast, sequences obtained in the other years differed from one another. A phylogenetic tree constructed from sequences recovered from patients without a history of travel abroad showed several clusters.

Conclusions

Our results suggest that (1) HAV acquired through homosexual activity may be transmitted to nonhomosexual individuals; (2) hepatitis A in metropolitan areas in Japan is caused mainly by sporadic infection with genotype IA HAV; and (3) several subtypes of genotype IA HAV are endemic in Japan.

Key words

hepatitis A virus epidemiology transmission route sexuality Japan 

Copyright information

© Springer-Verlag Tokyo 2006

Authors and Affiliations

  • Hideaki Takahashi
    • 1
  • Hiroshi Yotsuyanagi
    • 1
    • 3
  • Kiyomi Yasuda
    • 4
  • Tomohiko Koibuchi
    • 5
  • Michihiro Suzuki
    • 1
  • Tomohiro Kato
    • 2
  • Tetsuya Nakamura
    • 5
  • Aikichi Iwamoto
    • 5
  • Kusuki Nishioka
    • 2
  • Shiro Iino
    • 1
    • 4
  • Kazuhiko Koike
    • 3
  • Fumio Itoh
    • 1
  1. 1.Department of Internal Medicine, Division of Gastroenterology and HepatologyInstitute of Medical Science, St. Marianna UniversityKawasakiJapan
  2. 2.Division of Molecular ImmunologyInstitute of Medical Science, St. Marianna UniversityKawasakiJapan
  3. 3.Department of Infectious Diseases, Faculty of MedicineUniversity of TokyoTokyoJapan
  4. 4.Center for Liver DiseasesSeizankai Kiyokawa HospitalTokyoJapan
  5. 5.Department of Internal Medicine, Division of Infectious Diseases and ImmunologyInstitute of Medical Science, University of TokyoTokyoJapan

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