Daily text-based chief complaint data, March 23ÁMay 5, 2011, from 15 syndromic sites were obtained from EpiCenter (2) (funds provided by Utah Department of Health), mapped to 5 MLI syndromes (Table 1 ) and summarized using the Early Aberration Reporting System (EARS) (3) . Events of interest included all 'rash' events that contributed to an alert or had a concerning chief complaint (e.g., eye pain), all 'febrile rash' events that had a concerning chief complaint, all 'prodrome' events that had a concerning chief complaint, all 'case definition' events April 7, 2011 onward (date after which public health intervention was still possible) and all 'measles/testing' events. Visit notes, laboratory tests and results were obtained daily for each event of interest and reviewed for MLI. Summary findings, including diagnoses, laboratory results, rash descriptions and suspect exposures, were documented and non-MLI events were ruled out. Events of high suspicion for measles were further investigated via patient interview by phone and/or home visit.