Large scale use of SARS-CoV-2 antigen-based detection tests: a three-month experience in Guatemala, June-August 2020.

Objectives: To measure protocol adherence and antigen-based detection tests (AgDT) negative predictive value after 3 months of massive use as a diagnostic tool for COVID-19 in Guatemala.

Methods: The study period included nasopharyngeal swabs taken between March 12 and August 31, 2020, which results were entered in the national COVID-19 information system. Proportional increase in testing between one month before and one month after the introduction of AgDT (May 9-June 8 vs.