In addition to diarrhea, patients reported fatigue (86%), cramps (86%), body aches (71%), nausea (62%), headache (57%), chills (57%), fever (43%), vomiting (43%), and blood in stool (29%); none of the employees were hospitalized. No secondary cases in family members were identified. Five of eight stool specimens from eight patients submitted for culture were positive for SE. Among 33 workers in the production area, 18 (55%) had illness consistent with the case definition, compared with three (9%) of 34 workers in other areas of the facility (relative risk: 6.2; 95% confidence interval = 2.0-19.0). When analysis was restricted to workers in the production area, the strongest association with illness was working in room A. Eighteen (69%) of 26 employees who worked in room A (including those who did so intermittently) became ill, compared with none of the seven production-area workers who did not work in room A (p=0.002). During multiple visits to the facility, investigators noted inadequate handwashing and lack of PPE. Aside from working in room A, none of the exposures examined were significantly associated with illness.