Analysis of hepatitis B surface antigen mutations in Mongolia: molecular epidemiology and implications for mass vaccination.
Arch Virol
; 152(3): 575-84, 2007.
Article
em En
| MEDLINE
| ID: mdl-17115304
ABSTRACT
Although the potential significance of hepatitis B surface antigen (HBsAg) mutants for failure of immunization has been studied in some endemic countries, whether the "a" determinant variants are responsible for vaccine failure in Mongolia remains unknown. Fifty-nine HBsAg-positive children (age 8.8 +/- 0.9 years) who had been observed during the nationwide survey of vaccinated cohorts conducted in 2004 were subjected to molecular analyses of hepatitis B virus (HBV). Partial S gene sequences encoding amino acids (aa) 40-171 of HBsAg were determined in 57 children (96.6%) who had detectable HBV DNA. Phylogenetic analysis of the S gene sequences revealed that genotype D accounted for 93.0% and genotype A for 5.3%. Only one child (1.7%) had HBVs of genotypes A and D. HBsAg mutations were found in 17 (29.8%) children ranging from 1 to 4 aa per subject (mean +/- SD, 1.6 +/- 0.9 aa). Pro127Thr and Thr118Ala were the most common substitutions, which occurred in 6 (10.5%) and 3 (5.3%) subjects, respectively; none had Gly145Arg. There were no significant associations in the prevalence of HBsAg mutations with age, sex, residential area, or vaccination status against hepatitis B. Analysis of the deduced amino acid sequence of the entire preS1/preS2/S gene revealed that eight genotype D isolates and one genotype A isolate were quite similar to previously-reported wild-type isolates, suggesting that they are essentially wild-type, but not vaccine-induced mutants. In conclusion, the results demonstrate that hepatitis B surface gene mutants do not play a significant role in vaccination failure in Mongolia.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vírus da Hepatite B
/
Vacinas contra Hepatite B
/
Hepatite B
/
Antígenos de Superfície da Hepatite B
/
Mutação
Tipo de estudo:
Risk_factors_studies
/
Screening_studies
Limite:
Child
/
Female
/
Humans
/
Male
País/Região como assunto:
Asia
Idioma:
En
Revista:
Arch Virol
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Japão