Prevalence and characterization of hepatitis C virus genotype 4 in Japanese hepatitis C carriers.
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.
Hayashi
Kazuhiko
K
Second Department of Internal Medicine, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550, Nagoya, Japan
Fukuda
Yoshihide
Y
Nakano
Isao
I
Katano
Yoshiaki
Y
Toyoda
Hidenori
H
Yokozaki
Shouichi
S
Hayakawa
Tetsuo
T
Morita
Kiyoshi
K
Nishimura
Daisaku
D
Kato
Katsumoto
K
Urano
Fumihiro
F
Takamatsu
Junki
J