Consumption of prepackaged cookie dough cause of E. coli O157:H7 outbreak

Neil KP. Clin Infect Dis. 2011;doi:10.1093/cid/cir831.

Consumption of ready-to-bake commercially prepackaged cookie dough led to a nationwide outbreak of Shiga toxin-producing Escherichia coli O157:H7, affecting 77 people in 2009. Nearly 4 million packages of cookie dough were recalled, according to new findings published in Clinical Infectious Diseases.

“Consumers should not eat unbaked cookie dough or similar products that are intended to be cooked or baked before consumption,” Karen P. Neil, MD, MSPH, of the CDC’s National Center for Emerging and Zoonotic Infectious Diseases, told Infectious Disease News.

“Manufacturers should consider formulating ready-to-bake commercial prepackaged cookie dough to be as safe as a ready-to-eat food product.”

After the outbreak, the CDC collaborated with state and local public health officials to conduct traceback investigations and product testing to identify the source. Between March 16 and July 8, 2009, 77 patients across 30 states were identified as having Shiga toxin-producing E. coli (STEC) O157:H7 infections. Of these, 35 patients were hospitalized and 10 developed hemolytic uremic syndrome. Most patients were female (71%) and aged younger than 19 years (66%).

Results from a matched, case-control study indicated that 94% of case-patients consumed raw ready-to-bake commercially prepackaged cookie dough vs. only 11% of controls (OR=41.3; P<.001), according to the study. Despite instructions to bake cookie dough before eating, the researchers said this was a popular practice, especially among adolescent females, and is an ongoing risk to public health.

“This 2009 outbreak is the first time ready-to-bake commercially prepackaged cookie dough or a similar product has been implicated as a vehicle for E. coli O157 or other STEC infections,” Neil said. “The outbreak shows that more effective consumer education is needed about the risks of eating unbaked cookie dough and similar products that are intended to be cooked before consumption. Public health officials should consider food containing raw flour as possible vehicles of infection of future outbreaks of STEC or salmonella infections.”

Disclosure: The researchers report no relevant financial disclosures.

Follow InfectiousDiseaseNews.com on Twitter.