E. Coli Outbreak Linked to Chipotle Widens, With 52 Sickened in 9 States

— -- Health investigators announced that an E. coli_" target="_blank">E. coli outbreak linked to Chipotle restaurants was worse than previously realized, with at least 52 people infected in nine states.

The outbreak initially was reported in just Washington and Oregon, but has now spread to seven other states, including California, Illinois, Maryland, Minnesota, New York, Ohio and Pennsylvania.

Those infected range in ages from 1 to 94 years old and became sick between Oct. 19 to Nov. 13, according to the U.S. Centers for Disease Control and Prevention, which noted that 20 people were hospitalized in connection with the outbreak. E. coli symptoms can include severe stomach cramps, diarrhea, fever and vomiting. In rare occasions, a type of kidney failure can occur.

Of the 52 people interviewed by CDC investigators, 47 reported eating at a Chipotle Mexican Grill restaurant before becoming sick, according to the CDC.

Chipotle announced today that it would start implementing new food safety practices after consulting with experts.

"Chipotle’s enhanced food safety program is the product of a comprehensive reassessment of our food safety practices conducted with IEH Laboratories that included a farm-to-fork assessment of each ingredient we use with an eye toward establishing the highest standards for safety," the company said in a statement today on its Facebook page.

The new measures to ensure food safety and handling include testing fresh produce with DNA-based tests, start end-of-shelf-life testing to ensure ingredients are safe throughout their shelf life, look to improve the supply chain by measuring performance data of vendors and suppliers and enhance employee training in food safety and handling, according to the company.

Investigators are sequencing the bacterial DNA of the E. coli strain to figure out if there are other cases out there and to find a source for the outbreak, according to the CDC.

Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, said in an earlier interview that Chipotle's limited menu may have made it more difficult for investigators to detect the source of the outbreak. If a number of menu items share ingredients, it can be difficult to pinpoint which is the culprit for the outbreak, he noted.

"What you really need in order for the finger to be pointed at the source is for people to eat different things: People who eat A get sick and people eat B do not," Schaffner explained to ABC News. "Many of the ingredients, lettuce for example, can be on any number of different products."