Age-specific prevalence of antibodies to hepatitis A in children and adolescents from Rio de Janeiro, Brazil, 1978 and 1995. Relationship of prevalence to environmental factors.
The age-specific prevalence of antibodies to hepatitis A virus (anti-HAV) was determined in two different population groups with low socio-economic status from Rio de Janeiro city, Brazil, whose serum samples were collected 17 years apart (Population 1, 1978; Population 2, 1995). In Population 2, analysis of the anti-HAV prevalence was also carried out with respect to environmental factors. Population 1 was composed of 520 stored sera collected from the umbilical cord of term neonates and children aged 1 month to 6 years. In population 2, 720 serum samples were collected from children and adolescents with ages ranging from 1 to 23 years. The overall prevalence rate of anti-HAV in Population 1 and Population 2 was 65.6% and 32.1%, respectively. In Population 1, the anti-HAV prevalence reached 88% at the age of 3, while in Population 2, it increased from 4.5% in children under the age of 3 to 66% in the group of adolescents over the age of 14. The low exposure to HAV infection in younger children from Population 2 could be a result of improved environmental hygiene and sanitation, as demonstrated by the presence of piped water, waste and sewage disposal systems in most houses from this population group. These findings indicate a possible change in the prevalence of hepatitis A in Rio de Janeiro.
Departamento de Virologia, Instituto Oswaldo Cruz, Brasil.
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Vitral
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Yoshida
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Lemos
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Teixeira
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Gaspar
D000293:Adolescent; D000367:Age Factors; D001938:Brazil / Q000453:epidemiology; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D006506:Hepatitis A / Q000453:epidemiology* / Q000276:immunology*; D017957:Hepatitis A Virus, Human / Q000276:immunology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015995:Prevalence; D012189:Retrospective Studies; D012499:Sanitation; D016036:Seroepidemiologic Studies; D012923:Social Class