Molecular epidemiological study of hepatitis B virus infection in two different ethnic populations from the Solomon Islands.
The Solomon Islands is a multi-ethnic nation with a high rate of hepatitis B virus (HBV) infection. The prevalence relative to ethnicity was examined in relation to HBV infection, genotypes, and mutations. Asymptomatic populations (n = 564, 308 Melanesian and 118 Micronesian) from the Western Province were enrolled. Positive samples for Hepatitis B surface antigen (HBsAg) were examined for serological status, genotyping, viral load, and mutations of the basic core promoter (BCP) and pre-core (Pre-C) regions. The positive rate for HBsAg was 21.5%. The major Melanesian genotype was C (HBV/C), whereas the major Micronesian genotype was D (HBV/D). The prevalence of Hepatitis B e antigen (HBeAg) in serum was lower in carriers of HBV/D than of HBV/C. While the prevalence of the BCP mutation (T(1762)A(1764)) tended to be higher in HBV/C, that of the Pre-C mutation (T(1846)) was significantly higher in HBV/D (P < 0.0001). Genetic distance and phylogenetic analyses based on complete genome sequences were also carried out for two strains of HBV/C and two strains of HBV/D, and the findings were compared with those in the DDBJ/EMBL/GenBank database. The full-length sequence revealed that strains from the Solomon Islands were classified into subgenotype C3 (HBV/C3) and D4 (HBV/D4), and that the HBV/D strains were related closely to those from Papua New Guinea. HBV infection in the Solomon Islands is hyperendemic, and the genotype is ethnicity-specific. HBeAg appears to clear from the serum in young adulthood in HBV/D infection, which may be influenced by genotype-dependent features in relation to viral mutations.
Utsumi
Takako
T
Department of International and Environmental Medical Sciences, Kobe University Graduate School of Medicine, Kobe, Japan.
Yano
Yoshihiko
Y
Truong
Bui Xuan
BX
Tanaka
Yasuhito
Y
Mizokami
Masashi
M
Seo
Yasushi
Y
Kasuga
Masato
M
Kawabata
Masato
M
Hayashi
Yoshitake
Y
D000328:Adult; D002353:Carrier State / Q000821:virology; D004279:DNA, Viral / Q000235:genetics; D019353:Endemic Diseases; D005260:Female; D005838:Genotype; D006509:Hepatitis B / Q000453:epidemiology / Q000208:ethnology* / Q000821:virology*; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006513:Hepatitis B e Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008542:Melanesia / Q000453:epidemiology; D008875:Middle Aged; D017720:Molecular Epidemiology; D010802:Phylogeny; D017354:Point Mutation; D015995:Prevalence; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D019562:Viral Load
D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens