RESUMO
Avian influenza (AI) H9N2 has been reported from poultry in India. A seroepidemiological study was undertaken among poultry workers to understand the prevalence of antibodies against AI H9N2 in Pune, Maharashtra, India. A total of 338 poultry workers were sampled. Serum samples were tested for presence of antibodies against AI H9N2 virus by hemagglutination inhibition (HI) and microneutralization (MN) assays. A total of 249 baseline sera from general population from Pune were tested for antibodies against AI H9N2 and were negative by HI assay using ≥40 cut-off antibody titre. Overall 21 subjects (21/338â=â6.2%) were positive for antibodies against AI H9N2 by either HI or MN assays using ≥40 cut-off antibody titre. A total of 4.7% and 3.8% poultry workers were positive for antibodies against AI H9N2 by HI and MN assay respectively using 40 as cut-off antibody titre. This is the first report of seroprevalence of antibodies against AI H9N2 among poultry workers in India.
Assuntos
Doenças dos Trabalhadores Agrícolas/epidemiologia , Anticorpos Antivirais/sangue , Vírus da Influenza A Subtipo H9N2/imunologia , Influenza Aviária/epidemiologia , Influenza Humana/epidemiologia , Doenças dos Trabalhadores Agrícolas/imunologia , Doenças dos Trabalhadores Agrícolas/virologia , Animais , Testes de Inibição da Hemaglutinação , Humanos , Índia/epidemiologia , Influenza Aviária/imunologia , Influenza Aviária/transmissão , Influenza Humana/imunologia , Influenza Humana/virologia , Testes de Neutralização , Exposição Ocupacional , Aves Domésticas , Estudos SoroepidemiológicosRESUMO
In India, the first outbreak of pandemic influenza (H1N1) 2009 (H1N1pdm) was reported from Panchgani, Maharashtra, in June 2009. Studies from several countries have revealed different levels of pre-existing immunity to H1N1pdm 2009 in various age groups. This study was undertaken using age-stratified pre-pandemic human sera to understand baseline cross-reactivity of antibodies against H1N1pdm. Using cut off antibody titers 20 and 40, overall cross-reactivity was 2.1 and 0.9% respectively by microneutralization assay; 1.2% and 0.7% by haemagglutination inhibition assay, respectively. Results showed higher baseline antibodies and cross-reactive antibodies in the 0-19 age group whereas the elderly age group (≥60) showed no cross-reactivity to H1N1pdm. The higher baseline and cross-reactive antibodies in 0-19 years age group could be because of higher positivity to seasonal H1N1 in that age group. Overall, low level of cross-reactive antibodies to H1N1pdm virus were found in humans in pre-pandemic period in Maharashtra, India.
