Most E. coli Outbreaks Linked To Beef, Vegetable Row Crops

Three federal agencies have developed a new method for analyzing the foods from 17 broad categories responsible for foodborne illness outbreaks from 1998 to 2012 that were caused by Salmonella, E coli O157, Listeria monocytogenes, and Campylobacter. The pathogens were selected because of the frequency or severity of the illnesses they cause and because targeted interventions can have a significant impact in reducing them. The CDC has estimated that these four pathogens cause 1.9 million cases of foodborne illness in the U.S. each year.

The Interagency Food Safety Analytics Collaboration (IFSAC), a partnership that includes the CDC, the FDA, and the USDA’s Food Safety and Inspection Service (FSIS), issued the report in February in conjunction with a public meeting about the new method. The report, “Foodborne Illness Source Attribution Estimates for Salmonella, Escherichia coli O157 (E. coli O157), Listeria monocytogenes (Lm), and Campylobacter using Outbreak Surveillance Data,” states that more than 80 percent of E. coli O157 illnesses were attributed to beef and vegetable row crops, such as leafy vegetables. Illnesses attributed to Salmonella were broadly attributed across many food categories, although 77 percent were related to seeded vegetables, such as tomatoes, and eggs, fruits, chicken, sprouts, beef, and pork.

About 66 percent of Campylobacter illnesses were attributed to dairy, with most of those outbreaks related to raw milk or cheese produced from raw milk; 8 percent of Campylobacter illnesses were attributed to chicken. Fifty percent of Listeria illnesses were attributed to fruit and 31 percent to dairy. Due to limitations in outbreak data and uncertainty in the estimates, IFSAC recommends caution in interpreting certain findings, such as estimates for Campylobacter in dairy and Listeria in fruits. IFSAC suggests that the results be used with other scientific data for risk-based decision making.

David Goldman, MD, MPH, assistant administrator for the Office of Public Health Science at FSIS, says that most of the food industry regulated by FSIS is aware of the pathogens and food combinations that have historically led to illness. This “point-of-consumption attribution model” developed by IFSAC analyzes the type of food that was consumed by the affected individual and the pathogen that led to the illnesses. “We don’t know the places where the contamination took place, whether on the farm, in the processing plant, in transit, or in the kitchen.”

According to Christopher Braden, MD, director of the Division of Foodborne, Waterborne, and Environmental Diseases at the CDC, “industry realizes that when we are talking about a food category, that gives them some information about where they should focus. Then they need to go in and see where the hazards really exist among the different foods within those categories.”

Caroline Smith DeWaal, food safety director at the Center for Science in the Public Interest, says that even though she is pleased to see IFSAC “making some progress and engaging stakeholders, I am also concerned that the project is moving too slowly to provide meaningful information for FSMA implementation.” She says the expert panel convened at the public meeting should “provide information on the top hazards linked to food commodities.”

Holliman is a veteran journalist with extensive experience covering a variety of industries. Reach her at [email protected].