Carbon Live Fire Mexican Grill E. coli Outbreak Lawsuits - Illinois (2016)


On June 28, 2016, the Chicago Department of Public Health (CDPH) received five reports of Shiga-toxin producing Escherichia Coli (STEC) through routine surveillance.  By June 29, routine interviews conducted by CDPH Communicable Disease (CD) program revealed that three of the five cases reported consuming food items from one of Carbon’s two restaurant locations within two to three days before illness onset.  That evening, three separate hospitals reported an increase in the number of patients that presented to the emergency department with complaints of diarrhea and had preliminary positive STEC diagnostic laboratory tests.  By July 1, seven cases reported eating at one of Defendant Carbon’s two restaurant locations.

Carbon has two Chicago locations, one on the south side and another on  the west side of the city.  Both locations serve the same menu and use the same food suppliers. The majority of food preparation is done at the south side location; most food for the west side location is transported after preparation at the south side kitchen.  Staff members at each location regularly consume restaurant food.

After learning of the possible connection between the developing cluster of STEC illnesses and Carbon restaurant, CDPH issued a health alert to all Chicago hospitals to notify them of the outbreak and request prompt reporting of STEC cases.  Concurrently, the Illinois Department of Public Health (IDPH) issued an alert via the Foodborne Outbreak Network to state health departments to notify them of any STEC cases with travel to Chicago and mention of food consumption at Defendant Carbon’s restaurants prior to symptom onset.

As CDPH was notified of additional illness, investigators with that agency began interviewing sick persons (“cases”) and well restaurant meal companions of cases (“controls”) using a questionnaire that was created to collect information about symptoms of illness, food consumption, and other potential exposures occurring in the seven days prior to the onset of symptoms.  Ultimately, a “confirmed case” was defined as isolation of E. coli O157:H7 (STEC) from a clinical specimen in a person with illness onset between June 3 and July 23, 2016, with either reported exposure to Carbon’s restaurants or a pulsed field gel electrophoresis (PFGE) pattern indistinguishable from one of 14 patterns associated with the outbreak.  A “probable case” was defined as a person with clinically compatible illness (bloody diarrhea or at least three days of diarrhea, with at least three stools in a 24 hour period) in the absence of laboratory confirmation, and exposure to Carbon’s restaurants or a shared household with a primary confirmed case.  “Secondary cases” were defined as household contacts of primary confirmed or probable cases, with onset of diarrhea one to eight days after the primary case’s symptom onset date.

Concurrently with the epidemiological investigation discussed above, the CDPH Food Protection Division (FPD) conducted an environmental inspection of Carbon restaurants. Investigators collected food samples for testing, discussed food preparation with restaurant employees, and collected copies of invoices for food items.  Food handlers were asked to submit stool specimens to screen for STEC infection.

Sixty-nine confirmed and 37 probable cases were identified as part of this outbreak.  Twenty-one primary and one secondary case were hospitalized.  Nobody developed hemolytic uremic syndrome.  Among the 55 confirmed primary cases, 50 (91%) ate at the south side location (meal date range June 17 through 30 2016), and 5 (9%) ate at the west side location (meal date range June 19 through 26 2016).

Multiple food items were associated with illness on bivariate analysis including consumption of cilantro, salsa fresca, chicken taco, and lettuce.  Multivariable analysis using logistic regression revealed that consumption of cilantro, salsa fresca, and lettuce remained independently associated with illness after adjusting for age and gender.  The observed epidemiologic association with chicken tacos was believe to reflect collinearity between chicken tacos and cilantro, meaning that an association was identified because the chicken tacos are prepared and served with raw cilantro.  All cases who reported eating a chicken taco also reported eating cilantro.  Other chicken-containing items (e.g., chicken burritos, chicken salad bowls) were not associated with illness.  Because salsa fresca was known to contain raw cilantro, an additional multivariable logistic regression analysis was performed including a combined variable indicating consumption of either cilantro or salsa fresca.  In this model, consumption of cilantro or salsa fresca was associated with illness with an adjusted odds ratio of 6.9.  Lettuce was associated with illness in both multivariable models but was consumed by only 44% pf cases.  In comparison, cilantro was consumed by 87% of cases, and either cilantro or salsa fresca were consumed by 95% of cases.

FDP investigators identified several critical violations during their July 1, 2016 inspection of Carbon’s restaurant, including improper temperatures for several food items, and improper hand hygiene practices among food handlers.  Based on these findings and due to the concern for an ongoing public health threat associated with food served by Carbon, CDPH recommended that the restaurant voluntarily cease operations.  Management agreed and closed both Carbon locations.

CD investigators subsequently interviewed and tested 40 food handlers from both locations.  None reported any history of gastrointestinal illness in the two weeks preceding or during the outbreak period, but stool testing showed that 16 of the 40 food handlers tested in fact tested positive for STEC.

The specimens from the 69 confirmed cases and 16 positive food handlers produced 14 different PFGE patterns.  None of the 12 food items tested were positive for STEC.

Based on the finding that cilantro was the probable contaminated food item, CDPH, FDP and IDPH collected invoices from the restaurant for the outbreak period meal dates.  Cilantro was purchased from Defendant Martin Produce.  Investigators learned that Martin Produce had repacked cilantro from multiple sources prior to selling it to Carbon, including suppliers in Mexico and Illinois.  Investigators were unable to trace the contaminated cilantro back to its source, and did not conclude whether the cilantro had become contaminated by Martin Produce or during distribution prior to receipt by Martin Produce.

In conclusion, CDPH stated that “The large number of PFGE patterns associated with the outbreak was suggestive of a heavily contaminated food item rather than introduction from a point source such as an ill food worker at the restaurant,” but “cross-contamination during food preparation and transmission by food handlers who were found to have STEC infection likely contributed to the outbreak.”

Marler Clark represented 45 individuals affected by the outbreak, achieving settlements covering medical expenses, wage loss, pain and suffering, loss of normal life, and loss of spousal consortium.