Lettuce tainted with E. coli O157:H7 bacteria is the probably cause of an E. coli outbreak in Arizona linked to Federico’s Mexican Restaurant, located at 13132 W. Camelback Road, Litchfield Park, according to the final report issued by Maricopa County Department of Public Health (MCDPH) yesterday. The outbreak sickened 94 people who ate at the restaurant between July 18 and 30, 2013.
MCDPH was first notified of a potential cluster of E. coli illnesses on July 30, when a doctor reported seeing several patients with bloody diarrhea on the same day. All of these patients were members of the same high school sports team or family members of the team members.
An exposure questionnaire was emailed to all of the team members on July 31. The one consistent link revealed with the exposure history was eating at Federico’s Mexican Restaurant on July 23.
On August 1, MCDPH was notified that the pathogen causing the illnesses was E. coli, a dangerous pathogen due to shiga toxins created by the bacteria that poison the body. Two of these first cases developed hemolytic uremic syndrome (HUS), a severe complication that causes kidney failure when these toxins damage the kidneys.
On August 2, the outbreak investigation revealed that one ill teenager with bloody diarrhea had no connection to the high school sports team. This teenager had also eaten at the same Federico’s Mexican Restaurant on July 23, 2013. Then several other cases not related to the team were uncovered. All of them had eaten at Federico’s.
At this point, MCDPH alerted hospitals and physicians in Maricopa County and the Arizona Department of Health Services notified the FDA, other Arizona counties and foodborne disease epidemiologists throughout the state about the outbreak.
On August 6, MCDPH began contacting people who had eaten at the restaurant to determine if others were sickened in the outbreak.
On August 8, preliminary test results indicated that green salsa and lettuce found at the restaurant had high levels of coliforms, which indicates contamination with E. coli. On August 9, MCDPH collected more food samples from the implicated restaurant and a Federico’s restaurant in another location. Tests done on these and earlier food samples pointed to lettuce as the primary suspect, even though tests did not find E. coli bacteria, only high coliform counts.
On August 16, health officials reviewed the restaurant’s lettuce handling protocol, and observed that if a even a small amount of lettuce had been contaminated with E. coli, the bacteria could have easily spread to contaminate lettuce at the prep sink, shredder or during storage in a large container.
Traceback investigations found that Midwest Beef supplies beef and produce to Federico’s Mexican Restaurant. This supplier also provides food for other Federico’s Mexican Restaurant locations and other food service establishments, in Phoenix. No other confirmed cases of illness due to E. coli were reported from any of these other restaurant locations.
This post was written by Fred Pritzker, a national food safety lawyer who represents clients in personal injury and wrongful death lawsuits.