The purpose of this study is to determine the seroprevalence of Hepatitis A Virus (HAV), Varicella-Zoster virus (VZV), Cytomegalovirus (CMV), Herpes Simplex (HSV) and Bordetella pertussis (BP)infections in Mexico.

In order to document the epidemiological changes in the sero-prevalence of Hepatitis A, Human simplex virus (1 and 2), Varicella-Zoster virus and Cytomegalovirus infections, we propose to conduct a population based, seroprevalence, cross-sectional study, in Mexico. This will allow the identification of susceptible populations, which in turn, will serve as evidence for the elaboration of recommendations for the prevention of Hepatitis A, Human simplex virus, Varicella-Zoster virus and Cytomegalovirus infection in the region.

This study was conducted using data and serum samples from a random sample of subjects that participated in the 2006 National Health and Nutrition Survey.

Inclusion Criteria:

• Previously enrolled subjects aged >= 1 to 70 years for National Health and Nutrition Survey 2006 in Mexico, with previously obtained informed consent

Exclusion Criteria:

• Information required for the study is not available or incomplete.
• Inadequate or insufficient serum sample to detect viral agents required for the study.
• Serum sample wrongly identified.

The study population will include a random sample of 4000 subjects of subjects who participated in the 2006 National Health and Nutrition Survey (ENSANUT).