Genetic variability of hepatitis A virus isolates in Rio de Janeiro: implications for the vaccination of school children
Braz. j. med. biol. res
; 37(12): 1779-1787, Dec. 2004. ilus, tab, graf
Artigo
em Inglês
| LILACS
| ID: lil-388062
Biblioteca responsável:
BR1.1
ABSTRACT
The epidemiology of hepatitis A virus (HAV) infection is shifting from high to intermediate endemicity in Brazil, resulting in increased numbers of susceptible individuals and a greater potential for the emergence of outbreaks. Universal vaccination against HAV has been recommended for children, but updated sero-epidemiological data are necessary to analyze the level of natural immunity and to identify candidates for preventive measures. In addition, more molecular studies are necessary to characterize the genotypes involved in HAV infections and outbreaks. Sera from 299 school children (5-15 years old) and 25 school staff members, collected during an outbreak of HAV at a rural public school in June 2000, were tested for IgM and total anti-HAV antibodies (ELISA). Viral RNA was amplified by RT-PCR from anti-HAV IgM-positive sera and from 19 fecal samples. Direct nucleotide sequencing of the VP1/2A region was carried out on 18 PCR-positive samples. Acute HAV infection was detected by anti-HAV IgM in 93/299 children and in 3/25 adult staff members. The prevalence of total anti-HAV antibodies in IgM-negative children under 5 years of age was only 10.5 percent. HAV-RNA was detected in 46 percent IgM-positive serum samples and in 16 percent stool samples. Sequence analysis showed that half the isolates belonged to subgenotype IA and the other half to IB. On the basis of these data, mass vaccination against HAV is recommended without prevaccination screening, especially for children before they enter school, since nearly 90 percent of the children under 5 years were susceptible. Molecular characterization indicated the endemic circulation of specific HAV strains belonging to subgenotypes IA and IB.
Texto completo:
Disponível
Coleções:
Bases de dados internacionais
Contexto em Saúde:
ODS3 - Saúde e Bem-Estar
Problema de saúde:
Meta 3.3: Acabar com as doenças tropicais negligenciadas e combater as doenças transmissíveis
Base de dados:
LILACS
Assunto principal:
Variação Genética
/
Vírus da Hepatite A Humana
/
Hepatite A
Tipo de estudo:
Fatores de risco
Limite:
Adolescente
/
Adulto
/
Criança
/
Criança, pré-escolar
/
Humanos
País/Região como assunto:
América do Sul
/
Brasil
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
2004
Tipo de documento:
Artigo
País de afiliação:
Brasil
Instituição/País de afiliação:
Fiocruz/BR