Outbreak of influenza type A (H1N1) in Iporanga, Säo Paulo State, Brazil
Rev. Inst. Med. Trop. Säo Paulo
; 43(6): 311-315, Nov.-Dec. 2001. graf, tab
Article
em En
| LILACS
| ID: lil-303040
Biblioteca responsável:
BR1.1
ABSTRACT
From June to July 1999 an outbreak of acute respiratory illness occurred in the town of Iporanga. Out of a total of 4,837 inhabitants, 324 cases were notified to the Regional Surveillance Service. Influenza virus was isolated from 57.1 percent of the collected samples and 100 percent seroconversion to influenza A (H1N1) was obtained in 20 paired sera tested. The isolates were related to the A/Bayern/07/95 strain (H1N1). The percentages of cases notified during the outbreak were 28.4 percent, 29.0 percent, 20.7 percent, 6.2 percent and 15.7 percent in the age groups of 0-4, 5-9, 10-14, 15-19 and older than 20 years, respectively. The highest proportion of positives was observed among children younger than 14 years and no cases were notified in people older than 65 years, none of whom had been recently vaccinated against influenza. These findings suggest a significant vaccine protection against A/Bayern/7/95, the H1 component included in the 1997-98 influenza vaccine for elderly people. This viral strain is antigenically and genetically related to A/Beijing/262/95, the H1 component of the 1999 vaccine. Vaccines containing A/Beijing/262/95 (H1N1) stimulated post-immunization hemagglutination inhibition antibodies equivalent in frequency and titre to both A/Beijing/262/95-like and A/Bayern/7/95-like viruses. Thus, this investigation demonstrates the effectiveness of vaccination against influenza virus in the elderly
Texto completo:
1
Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
Vírus da Influenza A
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Surtos de Doenças
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Influenza Humana
Limite:
Adolescent
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Adult
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Child
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Child, preschool
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Humans
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Infant
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Newborn
País/Região como assunto:
America do sul
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Brasil
Idioma:
En
Ano de publicação:
2001
Tipo de documento:
Article