Seroprevalence study of infection with influenza A(H1N1)pdm09 virus in San Felipe Town, Chile

DOI: 10.4236/wjcd.2013.37075   PDF   HTML     3,128 Downloads   4,629 Views  


Objective: To know the natural history of the first wave of pandemic influenza A(H1N1)pdm09 in the Southern hemisphere, through the detection of antibodies against influenza A(H1N1)pdm09 in a selected community, to estimate the population attack rate and its variations, the consultation rates, hospitallization and mortality rates. Methodology: A representative random sample of the population of a commune in Chile (San Felipe) was interviewed and taken blood samples between January and March 2010. A study against the antibodies of the influenza A(H1N1) pdm09 virus was conducted, by the technique of the Hemaglutination Inhibition (HAI) according to standardized methodology. Subjects with antibody titers ≥1:40 were considered positive. Results: 13.5% of the population of San Felipe had antibodies against influenza A(H1N1)pdm09; this percentage reached 30% of the population between 0 and 18 years and 6.1% among those over 19 years. The age variable was the only factor that evidenced significant differences in the prevalence of antibodies. There were no significant differences related to gender, vaccination history against seasonal inluenza, or comorbidity. 51% of people with positive serology showed IN-FLUENZA-LIKE SYMPTOMS. Conclusions: A relevant percentage of subclinical disease was detected in the first pandemic

wave in Chile and the proportion of people with SARI and deaths was small. Data from epidemiological surveillance were useful to estimate the trend of TSI but not its magnitude.

Share and Cite:

Andrea, O. , Rodrigo, F. , Ximena, A. , Otavio, O. , Sergio, M. , Maritza, G. , Elena, P. , Manuel, N. , Andrea, G. , Patricia, B. , Judith, M. , Jeanette, V. , Jaime, C. , Katia, A. , Meg, M. , Marc-Alain, W. , Ernesto, C. , Sergio, A. , Sandra, Q. , Doris, G. and Claudia, G. (2013) Seroprevalence study of infection with influenza A(H1N1)pdm09 virus in San Felipe Town, Chile. World Journal of Cardiovascular Diseases, 3, 476-482. doi: 10.4236/wjcd.2013.37075.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Ministerio de Salud de Chile. Influenza pandémica (h1n1) (2009) Reporte Situación 2009. Ministerio de Salud de Chile, Enero de 2010.
[2] World Health Organization (2011) WHO Global Influenza Surveillance Network. Manual for the laboratory diagnosis and virological surveillance of influenza.
[3] (2009) WHO information for laboratory diagnosis of pandemic (H1N1) 2009 virus in humans.
[4] Ministerio de Salud de Chile (2010) Guía Clínica para el Diagnóstico y Manejo Clínico de Casos de Influenza Pandémica (H1N1) 2009, Versión: 4.0. Ministerio de Salud de Chile, Abril 2010.
[5] Tandale, B., Pawar, S., Gurav, Y., Chadha, M., Koratkar, S., Shelke, V., et al. (2010) Seroepidemiology of pandemic influenza A (H1N1) 2009 virus infections in Pune, India. BMC Infectious Diseases, 10, 255.
[6] Mahmud, S., Becker, M., Keynan, Y., Elliott, L., Thompson, L., Fowke, K., et al. (2010) Estimated cumulative incidence of pandemic (H1N1) influenza among pregnant women during the first wave of the 2009 pandemic. CMAJ, 182, 14.
[7] Miller, E., Hoschler, K., Hardelid, P., Stanford, E., Andrews, N. and Zambon, M. (2010) Incidence of 2009 pandemic influenza A H1N1 infection in England: A crosssectional serological study. Lancet, 375, 1100-1108.
[8] Tian, L.L., Shi, W.-X., Ying, D., Pang, X.-H., Peng, Y., Fang, H., Shu, J.C., Xin, Z., Zhang, D.-T. and Wang, Q.-Y. (2011) Serologic survey of pandemic influenza A (H1N1 2009) in Beijing, China. Preventive Medicine, 52, 71-74.
[9] Bandaranayake, D., Huang, Q.S., Bissielo, A., Wood, T., Mackereth, G., et al. (2010) Risk factors and immunity in a nationally representative population following the 2009 influenza A(H1N1) pandemic. PLoS ONE, 5, e13211.
[10] Gilbert, G.L., Cretikos, M.A., Hueston, L., Doukas, G., O’Toole, B., et al. (2010) Influenza A (H1N1) 2009 antibodies in residents of New South Wales, Australia, after the first pandemic wave in the 2009 Southern Hemisphere Winter. PLoS ONE, 5, e12562.
[11] Chao, D.-Y., Cheng, K.-F., Li, T.-C., Wu, T.-N., Chen, C.-Y., et al. (2011) Serological evidence of subclinical transmission of the 2009 pandemic H1N1 influenza virus outside of Mexico. PLoS ONE, 6, e14555.
[12] Ikonen, N., Strengell, M., Kinnunen, L., et al. (2009) High frequency of cross-reacting antibodies against 2009 pandemic influenza A(H1N1) virus among the elderly in Finland. Euro Surveill, 15, 19478.
[13] Rizzo, C., Rota, M.C., Bella, A., et al. (2010) Cross-reactive antibody responses to the 2009 A/(H1N1)v influenza virus in the Italian population in the pre-pandemic period. Vaccine, 28, 3558-3562.

comments powered by Disqus

Copyright © 2020 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.