On Halloween, Chipotle temporarily closed their restaurants in the Seattle and Portland, Oregon metropolitan areas, saying that they were protecting the public from an E. coli outbreak that had been linked to eating at Chipotle, but not to any particular food. This week, the story of this outbreak became stranger as the same strain of bacteria was found in people who had eaten at Chipotle restaurants in four other states. Wait… wasn’t this a regional outbreak?

That’s the mystery. There have been no new cases in the original outbreak states, Washington and Oregon: the Centers for Disease Control and Prevention put the total at 36 cases in Washington, and 13 in Oregon. Sixteen people were hospitalized, but none developed the serious kidney condition that can be a complication of E. coli, especially in young children, and none of the patients died.

There were two patients each in California and in Minnesota, and one each in New York and Ohio. That’s only the people who visited a medical professional and had samples taken: there are usually many more people who were sick but never made it to see a medical professional, instead choosing the “Netflix and ginger ale” treatment method.

Chipotle and public health authorities are still working to figure out which food item all of the people who got sick might have in common. Before cases in other states developed, the possibility that the culprit was some kind of produce shipped to Pacific Northwest restaurants made the most sense. The six patients outside of Oregon and Washington hadn’t traveled there recently, but most of them had eaten at Chipotle restaurants near their respective hometowns.

Notably, California and Minnesota were the sites of Chipotle’s other recent outbreaks of foodborne illness: contaminated tomatoes made diners sick in Minnesota back in September, and an unidentified foodborne illness, probably norovirus/Norwalk virus, made dozens of diners sick at a California restaurant. The cases aren’t connected, but could indicate some kind of food-handling issue.

The company’s top burrito, chairman and co-CEO Steve Ells, wrote an open letter published in major newspapers as an ad, explaining everything that Chipotle plans to do to prevent such an outbreak from happening again. Consumerist doesn’t accept ads, but we’ll show you the letter for free for the sake of completeness:

Multistate Outbreak of Shiga toxin-producing Escherichia coli O26 Infections Linked to Chipotle Mexican Grill Restaurants [CDC]

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