A recent outbreak of foodborne illness following a catered staff luncheon at Roosevelt High School in Des Moines, IA, sickened at least 58 people and canceled classes for the rest of the day on Oct. 22. A subsequent investigation by state and county health officials, summarized in a report released Wednesday, Nov. 4, 2015, found that meat served at the luncheon was contaminated with Clostridium perfringens. The meat was reportedly purchased and brought in to be served to staff members at the school luncheon, although officials would not reveal the type of meat nor its source, quoting state regulations. “I can’t reveal that due to our public health confidentiality laws. I can’t discuss the specific details of the case,” Nola Aigner, the spokeswoman for the Polk County Health Department, told a Des Moines newspaper. The report stated that investigators reviewed 103 questionnaires from people who were sickened following the school luncheon and those who weren’t. Food handlers were also interviewed and food and stool samples were tested by the State Hygienic Laboratory at the University of Iowa. Additional investigative work was done by officials with the Iowa Department of Inspections and Appeals. Amanda Lewis, a spokeswoman for the Des Moines Public Schools, said that the district was “relieved this is an isolated incidence of foodborne illness, that our teachers reported only short-term illnesses and that no students were involved.” Both Lewis and Aigner emphasized that the outbreak had refocused attention on the importance of following food safety guidelines and practices in the future. The Polk County Health Department report noted that while C. perfringens can be killed by cooking, the spores can survive and grow into new cells. “If cooked food is not promptly served or refrigerated, the spores can grow and produce new cells. C. perfringens can grow quickly at room temperature but cannot grow at refrigerator or freezer temperatures,” it stated. Recommendations to avoid the problem include: Cooking hot foods to the proper temperatures and, if allowed to cool down, reheating them to proper temperatures before serving; placing leftover food in shallow containers and immediately refrigerating or freezing them; keeping hot foods hot and cold foods cold when transporting food and/or serving food at a buffet. C. perfringens is a common foodborne pathogen which causes nearly 1 million cases of illness each year, according to the U.S. Centers for Disease Control and Prevention (CDC). “Beef, poultry, gravies, and dried or pre-cooked foods are common sources of C. perfringens infections,” CDC states. “C. perfringens infection often occurs when foods are prepared in large quantities and kept warm for a long time before serving. Outbreaks often happen in institutions, such as hospitals, school cafeterias, prisons, and nursing homes, or at events with catered food.” Additional safe food handling information and recommendations are available here. (To sign up for a free subscription to Food Safety News, click here.)