Distribution of HBV genotypes among HBV carriers in Benin:phylogenetic analysis and virological characteristics of HBV genotype E.
OBJECTIVE
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.


CONCLUSIONS
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.
Fujiwara
Kei
K
Department of Clinical Molecular Informative Medicine, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho, Nagoya 467-8601, Japan.
Tanaka
Yasuhito
Y
Orito
Etsuro
E
Ohno
Tomoyoshi
T
Kato
Takanobu
T
Sugihara
Kanji
K
Hasegawa
Izumi
I
Sakurai
Mayumi
M
Ito
Kiyoaki
K
Ozasa
Atsushi
A
Sakamoto
Yuko
Y
Arita
Isao
I
El-Gohary
Ahmed
A
Benoit
Agossou
A
Ogoundele-Akplogan
Sophie I
SI
Yoshihara
Namiko
N
Ueda
Ryuzo
R
Mizokami
Masashi
M
D000293:Adolescent; D000328:Adult; D001541:Benin / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology / Q000821:virology; D005260:Female; D005838:Genotype; D006509:Hepatitis B / Q000453:epidemiology* / Q000821:virology*; D006512:Hepatitis B Core Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008297:Male; D010802:Phylogeny
D006512:Hepatitis B Core Antigens