SEATTLE-- State health experts say the E. coli cases linked to Chipotle is most likely from fresh produce.
The cases across the Pacific Northwest went up from 22 to 37 on Tuesday.
Twenty-five of the 37 cases are from Western Washington.
There are eight Chipotle franchises across Washington and Oregon associated with the outbreak.
Five of the eight are in Washington.
They include Hazel Dell, 7715 NE 5th Avenue, Suite 109, in Vancouver; 1404 Broadway Avenue in Capitol Hill and 4229 University Way NE in Seattle; 512 Ramsey Way 101 in Kent ; 1753 S. Burlington Blvd. in Burlington.
“The exact source of illness for this outbreak still remains unknown,” Washington state health officer Kathy Lofy said.
With the help of the FDA, the state is seeking the common denominator of the E. coli outbreak at two different labs.
To complicate matters, the strain researchers are dealing with is a new one.
“Of the 25 patients associated with the outbreak, 10 have shown they have a Shiga toxin-producing called E. coli 0-26,” Lofy said.
With the majority of the foodborne illnesses linked to Chipotle, experts are testing a number of food samples, mostly fresh produce and spices from the restaurant.
“It’s unlikely to be a meat product; many of the diners didn’t eat meat products,” said Dr. Jeff Duchin with Public Heath – Seattle King County.
The 25 confirmed E. coli cases include Ashley Arellano who says she had a terrible pain in her kidney after eating at a Chipotle on October 14.
“I am grateful I wasn’t hospitalized or in a coma or worse, dead. I am not quite sure how bad it could have been,” Arellano said.
Nine people in Washington had to be hospitalized. Local attorney Bill Marler tells Q13 FOX News that two young girls -- an 8-year-old and a 14-year-old were among those hospitalized after eating at the Chipotle in Burlington.
“I think it’s a very good chance that we are going to end up with more cases,” Lofy said.
Moselle Freitas hopes she is not one of them; she ate at Chipotle twice last week.
"If it’s an issue with the tomatoes, onion, cilantro then I am at risk as well,” Freitas said.
Freitas says she will closely monitor her condition. Meanwhile, all Chipotle chains across Washington will remain closed until investigators find answers.
“I think proactively addressing to close the doors is a positive step in getting ahead of the story,” Freitas said.
Experts say if you have eaten at a Chipotle in the last three weeks, you need to seek medical care if you experience flu-like symptoms, abdominal cramps or blood in your stool.
In addition to the 25 confirmed cases in Western Washington, health officials say they are in the process of talking to another 25 people who could possibly have E. coli and have to be tested.