On Halloween, Chipotle closed 43 of their restaurants in Washington state and Oregon, “out of an abundance of caution” after people who had dined at six different Chipotle restaurants showed symptoms of E. coli infection. The restaurants remain closed while Chipotle and public health authorities figure out where the illness came from. Their preliminary declaration is that the bacteria hitched a ride on some vegetables.

Verifying who has a foodborne illness and who doesn’t is complex, since it requires matching samples from patients to the pathogen known to cause the outbreak. Authorities have three confirmed E. coli cases so far from people who have eaten at Chipotle in the last few weeks, and are testing more. They expect that the wide publicity that the outbreak is receiving will cause more people to come forward.

A spokesperson for the Oregon Public Health division says that they have no definitive ruling yet, but based on the information that the have, the outbreak most likely comes from contaminated produce.

Analyzing accounts from people who have become sick (verified or not) researchers found some food items in common. While most items sold at Chipotle have a meat base, the culprit appears to be a produce item, maybe a vegetables, and not contaminated and insufficiently cooked beef or chicken.

For older children and adults, E. coli is a miserable few das of diarrhea and abdominal pain. For children under 5 and adults who are elderly or already ill, complications from the illness can shut down the kidneys just a patient appears to be getting better.

Oregon official: Chipotle E. coli likely due to contaminated produce [USA Today]

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.