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©2005 Baishideng Publishing Group Inc. All rights reserved.
Distribution of HBV genotypes among HBV carriers in Benin:phylogenetic analysis and virological characteristics of HBV genotype E
Kei Fujiwara, Yasuhito Tanaka, Etsuro Orito, Tomoyoshi Ohno, Takanobu Kato, Kanji Sugihara, Izumi Hasegawa, Mayumi Sakurai, Kiyoaki Ito, Atsushi Ozasa, Yuko Sakamoto, Isao Arita, Ahmed El-Gohary, Agossou Benoit, Sophie I Ogoundele-Akplogan, Namiko Yoshihara, Ryuzo Ueda, Masashi Mizokami
Kei Fujiwara, Etsuro Orito, Tomoyoshi Ohno, Kanji Sugihara, Izumi Hasegawa, Mayumi Sakurai, Kiyoaki Ito, Atsushi Ozasa, Ryuzo Ueda, Department of Internal Medicine and Molecular Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
Yasuhito Tanaka, Takanobu Kato, Masashi Mizokami, Department of Clinical Molecular Informative Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
Yuko Sakamoto, Namiko Yoshihara, AIDS Research Center, National Institute of Infectious Disease, Tokyo, Japan
Isao Arita, Agency for Cooperation in International Health, Kumamoto, Japan
Ahmed El-Gohary, Clinical Pathology Department, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
Agossou Benoit, Central National Blood Transfusion Center, Cotonou, Benin
Sophie I Ogoundele-Akplogan, Hematology Lab-CNHUC, Cotonou, Benin
Author contributions: All authors contributed equally to the work.
Correspondence to: Dr Masashi Mizokami, Department of Clinical Molecular Informative Medicine, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho, Nagoya 467-8601, Japan. mizokami@med.nagoya-cu.ac.jp
Telephone: +81-52-853-8292 Fax: +81-52-842-0021
Received: February 15, 2005
Revised: March 20, 2005
Accepted: March 23, 2005
Published online: November 7, 2005
AIM: To determine the distribution of Hepatitis B virus (HBV) genotypes in Benin, and to clarify the virological characteristics of the dominant genotype.
METHODS: Among 500 blood donors in Benin, 21 HBsAg-positive donors were enrolled in the study. HBV genotypes were determined by enzyme immunoassay and restriction fragment length polymorphism. Complete genome sequences were determined by PCR and direct sequencing.
RESULTS: HBV genotype E (HBV/E) was detected in 20/21 (95.2%), and HBV/A in 1/21 (4.8%). From the age-specific prevalence of HBeAg to anti-HBe seroconversion (SC) in 19 HBV/E subjects, SC was estimated to occur frequently in late teens in HBV/E. The comparison of four complete HBV/E genomes from HBeAg-positive subjects in this study and five HBV/E sequences recruited from the database revealed that HBV/E was distributed throughout West Africa with very low genetic diversity (nucleotide homology 96.7-99.2%). Based on the sequences in the basic core promoter (BCP) to precore region of the nine HBV/E isolates compared to those of the other genotypes, a nucleotide substitution in the BCP, G1757A, was observed in HBV/E.
CONCLUSION: HBV/E is predominant in the Republic of Benin, and SC is estimated to occur in late teens in HBV/E. The specific nucleotide substitution G1757A in BCP, which might influence the virological characteristics, is observed in HBV/E.
