On Sunday, July 10, 2011 the Mount Sinai Hospital Emergency Department notified the City of Chicago Department of Public Health (CDPH) of a possible foodborne illness outbreak. Over the weekend at least 15 people had been seen at the hospital for gastrointestinal symptoms. Five patients were admitted. Laboratory analysis of stool specimens collected from two patients were positive for Salmonella. At least four ill persons reported eating at El Gran Burrito located at 1207 South Pulaski Road in Chicago in the 72 hours before symptom onset.
Ill customers had dined at the El Gran Burrito restaurant between July 6 and July 11. On Monday, July 11 CDPH staff informed Dr. Corland Lohff, state epidemiologist at the Illinois Department of Public Health (IDPH), of the ill patients and the suspected source, El Gran Burrito. CDPH staff began to interview ill persons about symptoms and possible exposures to a foodborne pathogen using a standardize questionnaire. Patient answers clearly implicated food prepared and sold at the El Gran Burrito restaurant located on South Pulaski Road.
Illness complaints among El Gran Burrito customers prompted CDPH restaurant inspectors to make an on-site visit to the restaurant on Monday, July 11. The restaurant “passed” inspection although food and non-food contact surfaces were in obvious need of cleaning. By July 12 more patient data were gathered and evidence connecting illnesses to the El Gran Burrito mounted. Leftover foods and environmental swabs were collected for laboratory analysis. CDPH staff met with employees to discuss food safety procedures, proper temperature controls, and good hygienic practices. El Gran Burrito voluntarily closed on July 12 for thorough cleaning and sanitizing.
Patient stool specimens were serotype as Salmonella serotype Newport. Genetic testing of isolates obtained from stool cultures was conducted by pulsed field gel electrophoresis (PFGE). Molecular tests results solidified evidence of an outbreak of salmonellosis among customers of El Gran Burrito. Ill El Gran Burrito patrons shared a common genetic strain of Salmonella Newport identified as JJPX01.0166/JJPA6.0146. The IDPH assigned identification number IL2011-122 to the outbreak.