Officials have confirmed that three cases in Oregon involve people who ate at Chipotle restaurants in Clackamas and Washington counties. Nine of the Washington cases were linked to a restaurant in Clark County and the remaining 10 were tracked to locations in Cowlitz, King and Skagit counties.
So far, eight people have been hospitalized, seven from Washington and one from Oregon. The outbreak has prompted the Denver-based burrito chain to suspend operations at dozens of locations. Chipotle Mexican has over 1,500 restaurants in the U.S. and beyond.
According to the Oregon Health Authority, the strain is shiga toxin-producing E. coli, which can be transmitted through contaminated food or water, or through contact with animals or people.
Officials are asking anyone who dined at a Chipotle restaurant between October 14 and 23 who suffered bouts of vomiting or bloody diarrhea to see their doctors and tell them about the outbreak.
The number of people affected "is likely more than identified" because not everyone seeks medical help after becoming ill, Oregon health officials said in a news release.