Why does it take so long to identify what is causing an outbreak of foodborne illness?
That’s a great question, but the length of some of these investigations makes sense once you start thinking about it. The official definition of a foodborne disease outbreak is “an incident in which two or more persons experience a similar illness resulting from the ingestion of a common food.” In some cases, the cause of an outbreak isn’t difficult to track down. When a group of people who have attended the same event and ate the same food report similar cases of gastrointestinal illness, it’s often quick work to pinpoint the cause. But public health officials say the hardest outbreaks to detect are those that are spread over a large geographic area. That’s been the case for many high-profile outbreaks in recent years. Twenty years ago, these outbreaks may never have even been identified — authorities didn’t have the tools to link isolated cases together. You might recall the 1993 E. coli O157:H7 outbreak in Oregon and other Western states in which hundreds became ill and four childr
