The number of E. coli food-poisoning cases associated with Chipotle restaurants in the Northwest is continuously rising, with the number reaching 29 in Washington. On Wednesday, health officials reported that in Oregon the number has gone down from 12 to 10, however, a total of 39 are confirmed in the outbreak.

So far, 14 people have been hospitalized, with no reports of deaths. The Mexican fast-food chain's operated 43 restaurants remained shut in the 2 states as regional health officials scramble to know the genetic fingerprint of specific cases and federal officials have designated outbreak-response teams for help.

Many of the cases seem to be caused by E. coli O26, so far. E. coli O26 is a strain producing Shiga toxins that can result into serious illness.

As per a report posted on late Wednesday by the Centers for Disease Control and Prevention (CDC), the tests carried on eight ill people, including 5 from Washington and 3 from Oregon, have indicated that all of them were infected by Shiga toxin-producing E. coli O26 having the same DNA fingerprint.. It will test more samples.

Health officials have suspected that fresh produce was the culprit, but test results of food from the restaurant sites, and the supply chain are awaited.

In an email, Danielle Kenneweg, a spokeswoman for the Washington State Department of Health, said, "It is possible that we will get some preliminary food-testing results by the end of the week. We don't know yet if that information will be complete enough and ready for sharing".