The system evaluation was based on the CDC Guidelines for Evaluating Public Health Surveillance Systems, 2001. Data source included  measles' surveillance database, case investigation forms, and reports from the Serology Reference Laboratory. All patients registered in the database were considered the study population.  Criteria used for evaluation included: timeliness: samples arriving at the laboratory within 15 days and results issued within four days; Data quality: adequate samples and completeness of case investigation forms; Stability: time that the laboratory has operated without failure (months); and Sensitivity: Suspected cases with samples collected. We also compared the positivity rate before and during COVID-19. For data analysis, the Microsoft Office Excel 2013 was used.