title: Prevalence and characterization of hepatitis C virus genotype 4 in Japanese hepatitis C carriers.
abstract: Hepatitis C virus (HCV) can be classified into six major genotypes, the prevalences of which differ around the world. In Japan, the main genotypes are HCV 1 and HCV 2; others are found only rarely. Little is known about the prevalence in Japan of HCV genotype 4 which, is found frequently in North and Central Africa and the Middle East. Thus, we conducted a study to clarify distribution of HCV genotype 4 and the clinical demographics of patients with HCV genotype 4 in Japan. We examined HCV genotypes in 899 Japanese individuals with HCV viremia living in Aichi Prefecture, including 63 hemophiliacs. Four patients (0.4%) were infected with HCV genotype 4. All four of these patients were male hemophiliacs who had received clotting factors from foreign countries. Three patients were co-infected with human immunodeficiency virus (HIV); none were co-infected with GB virus-C/hepatitis G virus. Phylogenetic analysis of the El region indicated that all four patients were infected with subtype 4a. This subtype is related genetically to a subtype previously reported in Japanese and Italian hemophiliacs. HCV genotype 4 is indeed rare in Japan and may be detected only among hemophiliacs who have received inactivated clotting factor concentrates from foreign countries.
authors.affiliation: Second Department of Internal Medicine, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550, Nagoya, Japan
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Hayashi
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Fukuda
authors.forename: Isao
authors.initials: I
authors.lastname: Nakano
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Katano
authors.forename: Hidenori
authors.initials: H
authors.lastname: Toyoda
authors.forename: Shouichi
authors.initials: S
authors.lastname: Yokozaki
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Hayakawa
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Morita
authors.forename: Daisaku
authors.initials: D
authors.lastname: Nishimura
authors.forename: Katsumoto
authors.initials: K
authors.lastname: Kato
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Urano
authors.forename: Junki
authors.initials: J
authors.lastname: Takamatsu