Since 1987, Mexico has established periodical health surveys (ENSA) for surveillance of Mexican population-based health metrics. In this study, we propose to use data and samples collected from the survey performed in 2000, the ENSA 2000. This survey was a probabilistic, multi-stage, stratified, cluster household survey conducted by the Mexican Secretariat of Health from November 1999 to June 2000. Research design and methods have been described elsewhere . Participants were randomly selected in order to be representative of the civilian, non-institutionalized Mexican population, at the state and national levels. Trained personnel conducted the interviews. Information was collected on household and sociodemographic characteristics, current health status, health care service usage, and behavioural aspects of participants. Sera and buffy coats were obtained from 43,085 individuals aged 20 years or older. More than fifty publications have arisen from this survey providing critical insights into the status of national health alongside some genetic traits of the sampled population . In particular, the inclusion of individuals from remote and rural locations in Mexico makes this survey unique. Given its large volume, sophisticated sampling design, breadth of demographic sampling and extensive trait data, the ENSA 2000 represents a valuable untapped genetic resource to link genetic markers and health outcomes. The effective genetic characterization of such a database is now possible by bringing together a diverse team with expertise in Public Health, Epidemiology, Immunology, Paediatrics, Population Genetics, and Statistical and Computational Genomics.
Working with the National Health Surveys in Mexico provides a range of benefits. Firstly, the Surveys have reported on a range of medical conditions of high relevance to the country. Figuring prominently among these are traits that are established risk factors in the development of cardiovascular and metabolic disease as well as a range of seroprevalence estimates for diverse infectious diseases that have helped inform preventative interventions including vaccination against hepatitis A and VZV [3-6]. Secondly, a major breakthrough has recently occurred with the generation of a fine-scale genetic map of ethnic variation  in Mexico, revealing extremely high levels of genetic differentiation in the Mexican population, particularly among individuals of indigenous ancestry. This diversity was shown to have clear, replicated associations in physiological measures of lung function. Thus, Mexico constitutes a unique opportunity to explore deep population substructures in traits related to health and disease through the study of established cohorts, particularly for highly heritable traits with large genetic effects. We will specifically leverage this population substructure map to help shape and refine our discoveries through genetic association studies looking at multiple biomedical traits that have been demonstrated to have a clear heritable component.
6. Caballero-Ortega, H., et al., Seroprevalence and national distribution of human toxoplasmosis in Mexico: analysis of the 2000 and 2006 National Health Surveys. Trans R Soc Trop Med Hyg, 2012. 106(11): p. 653-9.