Building Better Outbreak Investigations: From Detection to Source
Craig W. Hedberg, Division of Environmental and Occupational Health, University of Minnesota School of Public Health, Minneapolis, MN 55455
Outbreak investigations are critical to identify new food safety hazards and provide feedback on the effectiveness of food safety systems. Outbreaks are detected in one of two ways: 1) illnesses associated with events or establishments and 2) case clusters identified through pathogen-specific surveillance. The first requires prompt, thorough investigation to identify the agent and the source. This may be the only way to identify "new" foodborne pathogens, such as diarrheogenic E. coli, or Cyclospora. The second requires epidemiologic investigation, aided by molecular subtyping, to identify the source. Both require close collaboration between epidemiologists and public health laboratories. Both also require close collaboration with environmental health specialists and field investigators to identify and trace the source of potential vehicles. Although product trace backs are frequently started only after a food item has been implicated, detailed product information is actually critical to epidemiologic analysis. Thus, collecting product source information should begin as early in the investigation as possible. This will help build the better investigations that are needed to improve the safety of our food supply.