Infection with influenza A(H1N1)pdm09 during the first wave of the 2009 pandemic: Evidence from a longitudinal seroepidemiologic study in Dhaka, Bangladesh.
Influenza Other Respir Viruses
; 11(5): 394-398, 2017 09.
Article
em En
| MEDLINE
| ID: mdl-28688210
ABSTRACT
BACKGROUND:
We determined influenza A(H1N1)pdm09 antibody levels before and after the first wave of the pandemic in an urban community in Dhaka, Bangladesh.METHODS:
We identified a cohort of households by stratified random sampling. We collected baseline serum specimens during July-August 2009, just prior to the initial wave of the 2009 pandemic in this community and a second specimen during November 2009, after the pandemic peak. Paired sera were tested for antibodies against A(H1N1)pdm09 virus using microneutralization assay and hemagglutinin inhibition (HI) assay. A fourfold increase in antibody titer by either assay with a titer of ≥40 in the convalescent sera was considered a seroconversion. At baseline, an HI titer of ≥40 was considered seropositive. We collected information on clinical illness from weekly home visits.RESULTS:
We tested 779 paired sera from the participants. At baseline, before the pandemic wave, 1% overall and 3% of persons >60 years old were seropositive. After the first wave of the pandemic, 211 (27%) individuals seroconverted against A(H1N1)pdm09. Children aged 5-17 years had the highest proportion (37%) of seroconversion. Among 264 (34%) persons with information on clinical illness, 191 (72%) had illness >3 weeks prior to collection of the follow-up sera and 73 (38%) seroconverted. Sixteen (22%) of these 73 seroconverted participants reported no clinical illness.CONCLUSION:
After the first pandemic wave in Dhaka, one in four persons were infected by A(H1N1)pdm09 virus and the highest burden of infection was among the school-aged children. Seroprevalence studies supplement traditional surveillance systems to estimate infection burden.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Estudos Soroepidemiológicos
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Influenza Humana
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Vírus da Influenza A Subtipo H1N1
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Pandemias
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Anticorpos Antivirais
Tipo de estudo:
Etiology_studies
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Incidence_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Adolescent
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Adult
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Aged
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Child
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Child, preschool
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Female
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Humans
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Infant
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Male
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Middle aged
País como assunto:
Asia
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article