Table of Contents
Influenza Research and Treatment
Volume 2012 (2012), Article ID 501784, 5 pages
Research Article

Comparing Deaths from Influenza H1N1 and Seasonal Influenza A: Main Sociodemographic and Clinical Differences between the Most Prevalent 2009 Viruses

1Ministry of Health, 06600 Mexico City, DF, Mexico
2Center for Evaluation Research and Surveys, National Institute of Public Health, 62100 Cuernavaca, MOR, Mexico
3Health Policy Unit, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
4Ixtapaluca Highly Specialized Regional Hospital, Ministry of Health, 56530 Ixtapaluca, MEX, Mexico

Received 6 June 2012; Revised 4 December 2012; Accepted 11 December 2012

Academic Editor: Michael L. Perdue

Copyright © 2012 German Fajardo-Dolci et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background. During the 2009 spring epidemic outbreak in Mexico, an important research and policy question faced was related to the differences in clinical profile and population characteristics of those affected by the new H1N1 virus compared with the seasonal virus. Methods and Findings. Data from clinical files from all influenza A deaths in Mexico between April 10 and July 13, 2009 were analyzed to describe differences in clinical and socioeconomic profile between H1N1 and non-H1N1 cases. A total of 324 influenza A mortality cases were studied of which 239 presented rt-PCR confirmation for H1N1 virus and 85 for seasonal influenza A. From the differences of means and multivariate logistic regression, it was found that H1N1 deaths occurred in younger and less educated people, and among those who engage in activities where there is increased contact with other unknown persons (OR 4.52, 95% CI 1.56–13.14). Clinical symptoms were similar except for dyspnea, headache, and chest pain that were less frequently found among H1N1 cases. Conclusions. Findings suggest that age, education, and occupation are factors that may be useful to identify risk for H1N1 among influenza cases, and also that patients with early dyspnea, headache, and chest pain are more likely to be non-H1N1 cases.