"We can't be certain that raw cookie dough is the source of these infections, but we are concerned enough that it might be and want consumers to be aware," said Alicia Cronquist, foodborne disease epidemiologist at the Colorado health department, in a Thursday statement.
Of five cases of E. coli infection in Colorado, the four people interviewed so far by the state health department ate raw cookie dough. Two of those people have been hospitalized, according to the Colorado Department of Health.
The spread of E. coli infection across several states indicates the possible contamination may have happened at a manufacturing facility before the product was shipped out to various regions of the country, Marler said.
That's precisely the type of situation that a bill approved by a House committee on Capitol Hill earlier this week aims to prevent. A food safety measure is now headed to the full House for consideration.
The bill being considered would give FDA new authority intended to improve food safety. It would ramp up inspections of food facilities and call for those facilities to pay an annual registration fee that would help the FDA collect money to conduct inspections.
"A series of foodborne disease outbreaks -- in spinach, peanuts, and peppers, to name a few -- has not only sickened and killed American consumers, but has shaken public confidence in the industry that produces one of our most basic and important commodities," House Commerce committee chairman Henry Waxman, D- Calif., said Wednesday. "And it has laid bare unacceptable gaps in our food safety laws."
The measure has support from the Grocery Manufacturers Association as well as other consumer and food industry groups.
For more information or questions about Nestle Toll House raw cookie dough, people can contact the company by calling 1-800-559-5025 or visiting the Web site, www.verybestbaking.com.
ABC News' Brian Hartman contributed to this report.