State and federal officials believe that dough used by Pizza Ranch restaurants for desserts was the likely cause in a nine-state E. coli outbreak that started in December and continued through early February this year. Thirteen people have been confirmed as outbreak victims, with eight of them requiring hospitalization, said David Steigman, a spokesman for the Food and Drug Administration. “Pizza Ranch discontinued the use of the dough and dough mixes on Feb. 4,” Steigman said today. “All of the dough was discarded by Feb. 6.” Steigman said the outbreak investigation in still ongoing with various state agencies and the U.S. Centers for Disease Control and Prevention working together to confirm the root cause. A CDC spokeswoman told the Des Moines Register newspaper that two children who were outbreak victims developed kidney failure, but that they are recovering, Pizza Ranch, based in Orange City, IA, has about 190 restaurants in 13 states. Its administration and individual store managers have been working with investigators for weeks, according to a written statement issued by Ryan Achterhoff, chief administrative officer. “Since late January, we have been assisting public health officials who are investigating 13 cases of illness attributed to a specific strain of E. Coli O157 bacteria,” Achterhoff said. “Nine of the affected individuals reported having eaten at nine different Pizza Ranches in seven states. There are also individuals multiple states away from the nearest Pizza Ranch that reported not eating at Pizza Ranch that have the same strain of E. Coli O157, though health investigators have not been able to pinpoint how they contracted the strain.” As a precaution, Pizza Ranch stopped using its Skillet Dough mix immediately “in response to information suggesting that this product was a possible common factor in the illnesses and subsequently expanded this product withdrawal to include our Original Dough mix,” Achterhoff said. Neither the FDA nor the CDC had posted any information about the outbreak or investigation as of 2 p.m. EDT today, but Pizza Ranch officials say none of the product samples collected and tested by governmental agencies showed E. coli contamination. “The fact pattern shows that the source of bacteria originated from an outside supplier rather than at our restaurants. … Pizza Ranch independently ran over 40 tests on different products to test for the presence of E. Coli O157 and it was not found in any products tested,” according to Achterhoff’s statement. “We provided public health investigators with a list of all of our ingredients as well as contact information for our ingredient suppliers. We also contacted the supplier of our dough mixes regarding this issue with the request that they cooperate with state and federal health officials. Pizza Ranch has also ceased using this outside supplier to supply its dough mix.” All Pizza Ranch locations are open and serving their full menus, Achterhoff said. “In addition, we instructed all Pizza Ranch locations to complete a special, precautionary cleaning of all surfaces and equipment used in dough preparation or service.” E. coli infections can cause serious illness, sometimes leading to kidney failure and death, according to the CDC.   (To sign up for a free subscription to Food Safety News, click here.)