Negative studies are helpful to compute the specificity of diagnostic tests: measuring Trypanosoma cruzi seroprevalence in Guanajuato, Mexico

Abstract

Background: Publishing negative seroprevalence studies not only helps to have more accurate seroprevalence estimates but also allows calculating the specificity of the diagnostic tests used. We performed a population-based Trypanosoma cruzi seroprevalence survey in a community in central Mexico. Results: We surveyed 204 women and children and collected blood by finger prick. We performed rapid tests (Stat-Pak, Chembio, Inc., Medford, New York) and recombinant Chagas ELISA tests v3.0 (Wiener, Rosario, Argentina). All rapid tests and all ELISA tests were negative. Conclusion: The rapid test had 100 % of specificity compared to the ELISA.