More Chipotle E. Coli cases confirmed in Ore., Wash.

There are now more than three dozen confirmed cases of people being sickened by an E. coli outbreak in Oregon and Washington state, a sharp increase in the number of people affected by an outbreak that has led to the popular fast casual chain Chipotle Mexican Grill temporarily closing 43 restaurants in the Pacific Northwest.

Katrina Hedberg, an epidemiologist with the Oregon Health Authority, said on Tuesday there are 12 confirmed cases in the state, up from the three confirmed cases state health officials reported on Saturday. Hedberg said at least eight of those stricken became ill after eating at a Chipotle restaurant.

Meanwhile, public health officials in Washington reported six new confirmed cases of E. coli, bringing the total sickened in the outbreak in the state to 25. Kathy Lofy, Washington state's health officer, said 23 of the 25 people ate at Chipotle.

"We are encouraging anyone who has eaten at a Chipotle restaurant and has developed severe diarrhea or bloody diarrhea (to) seek health care," said Hedberg, who added that most of those who became ill in Oregon were from the Portland area. "At this point, we still think our case count may increase."

Meanwhile, a Kelso, Wash., woman who ate a burrito bowl  at a Chipotle in Vancouver, Wash., sued the restaurant chain saying she is among those who became infected after eating at Chipotle.

Charmaine Denise Mode said she ate the burrito bowl on Oct. 21 and became sickened four days later with severe diarrhea.

On Oct. 26, Mode, who is a registered nurse, began experiencing bloody diarrhea—a telltale sign of an E. coli infection, according to the lawsuit. The following day she sought treatment, and a stool sample tested positive for shiga-toxin producing E. coli. The lawsuit noted that Mode had to endure a painful examination.

Mode, who filed the lawsuit on Monday, seeks $75,000 in damages.

Chris Arnold, a spokesman for the Denver-headquartered Chipotle, declined to comment on the lawsuit.

167,427 pounds of beef recalled for possible E. coli

Chipotle has voluntarily closed locations in Oregon and Washington, while health officials investigate the matter. On Tuesday, the company announced it has taken a number of steps in the aftermath of the crisis, including conducting environmental and food testing in its restaurants and distribution centers,deep cleaning of the closed restaurants, and hiring two food safety consulting firms to assess and potentially bolster the company's food safety procedures.

“The safety of our customers and integrity of our food supply has always been our highest priority,” said Steve Ells, chairman and co-CEO of Chipotle, in a statement. “We work with a number of very fresh ingredients in order to serve our customers the highest-quality, best-tasting food we can. If there are opportunities to do better, we will push ourselves to find them and enhance our already high standards for food safety."

Hedberg said early indications suggest that the source of the E. coli came from produce. She added that the contamination likely happened at the distributor or supplier level.

"We need to figure out what the food item is so that we can stop it upstream," Hedberg said.

Health officials in both states have called on anyone who ate at Chipotle restaurants and became ill with vomiting and bloody diarrhea to seek treatment and let physicians know about the possible connection. People stricken with E. coli most commonly suffer watery or bloody diarrhea and stomach cramps one to 10 days after consuming contaminated food. In the most extreme cases, E. coli can be deadly.

Oregon official: Chipotle E. coli likely due to contaminated produce

The latest incident marks the third outbreak of foodborne illness at Chipotle restaurants this year.

In August, a Chipotle restaurant in Simi Valley, Calif. was temporarily closed after 80 customers and 18 employees reported symptoms of Norovirus. The restaurant was reopened after restaurant operators did a deep cleaning of the store.

Also in August, Minnesota health and agriculture officials reported an outbreak of salmonella among customers of 17 different Chipotle restaurants located primarily in the Twin Cities metro area. Minnesota Department of Health officials cited tomatoes as the cause of outbreak, which affected 64 customers. Nine of those sickened customers were hospitalized.