Quantifying the mortality caused by the H1N1 influenza virus during the 2009 pandemic in Mexico

  • Eusebio Perez-Flores Coordination of Health Research, Mexican Social Security Institute (IMSS), Mexico City, Mexico
  • Juan Carlos Izquierdo-Puente Coordination of Epidemiological Surveillance and Contingencies Support, IMSS, Mexico City, Mexico
  • Jose Juan Castillo-Perez Coordination of Health Research, Mexican Social Security Institute (IMSS), Mexico City, Mexico
  • Gustavo Ramírez-Rosales Coordination of Epidemiological Surveillance and Contingencies Support, IMSS, Mexico City, Mexico
  • Israel Grijalva-Otero Coordination of Health Research, Mexican Social Security Institute (IMSS), Mexico City, Mexico
  • Constantino Lopez-Macias Medical Research Unit on Immunochemistry, Specialties Hospital of the National Medical Centre Siglo XXI, IMSS, Mexico City, Mexico
  • Roman Alejandro Garcia-Ramirez Research Unit on Clinical Epidemiology, Pediatric Hospital of the National Medical Centre Siglo XXI, IMSS, Mexico City, Mexico
  • Concepción Grajales-Muñiz Coordination of Epidemiological Surveillance and Contingencies Support, IMSS, Mexico City, Mexico
  • Juan Manuel Mejia-Arangure Coordination of Health Research, Mexican Social Security Institute (IMSS), Mexico City, Mexico
Keywords: influenza A virus H1N1 subtype, pandemics, public health, disease outbreaks, statistics, population

Abstract

Introduction: The frequency and mortality of the pandemic caused by influenza A(H1N1)pdm09 might have been underestimated, especially in developing countries. This study was designed to quantify the possible underestimation of pandemic influenza mortality and evaluate the concordance between the data reported for A(H1N1)pdm09 mortality and the causes of death reported during the pandemic period of April 2009 to February 2010.

Methodology: The death certificates of 754 confirmed cases of A(H1N1)pdm09 infection were included in the study. Data was analyzed using the United States Centers for Disease Control and Prevention’s statistical model accounts for the variability in the proportion at each step using the Monte Carlo probabilistic model sampled from a uniform probability distribution.

Results: A total of 1,969 deaths were estimated, with an estimated lethality of 5.53 per 100,000 (range, 3.5-8.76 per 100,000) in contrast with the 754 deaths and a lethality of 1.98 per 100,000 infected patients officially reported. In 631 of 754 (83.7%) death certificates from A(H1N1)pdm09 influenza-positive patients, influenza was not mentioned as a cause of death.

Conclusions: It is possible that the mortality of the pandemic was three times higher than officially reported in Mexico. One source of error that could explain this underestimation is in the completion of death certificates, because in > 80% of confirmed cases of infection with influenza virus, it was not reported as the cause of death.

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Author Biography

Juan Manuel Mejia-Arangure, Coordination of Health Research, Mexican Social Security Institute (IMSS), Mexico City, Mexico
Executive Secretary, National Comission of the Research in Health, Mexican Institute of the Social Security
Published
2014-06-11
How to Cite
1.
Perez-FloresE, Izquierdo-PuenteJC, Castillo-PerezJJ, Ramírez-RosalesG, Grijalva-OteroI, Lopez-MaciasC, Garcia-RamirezRA, Grajales-MuñizC, Mejia-ArangureJM (2014) Quantifying the mortality caused by the H1N1 influenza virus during the 2009 pandemic in Mexico. J Infect Dev Ctries 8:742-748. doi: 10.3855/jidc.3622
Section
Original Articles