[Anti-SARS-CoV-2 seroprevalence in administrative staff of the Mexican Institute for Social Security].

Background: Asymptomatic subjects, the lack of diagnostic tests and, in countries like Mexico, the epidemiological surveillance method does not allow to establish the real number of infections in the COVID-19 pandemic. Frontline health personnel, as well as other groups related to priority activities are considered of high risk. We included administrative workers in contact with health personnel in the hospital units of the Mexican Institute for Social Security (IMSS, according to its initials in Spanish).