Define the term "foodborne illness outbreak."

An outbreak of foodborne illness occurs when two or more of people who eat the same food get the same illness. It may be a group that ate a meal together somewhere, or it may be a group of people who do not know each other at all, but who all happened to buy and eat the same contaminated item from a grocery store or restaurant.

Many outbreaks are local in nature. They are recognized when a group of people realizes that they all became ill after eating a common meal, and someone calls the local health department. This classic local outbreak might follow a catered meal at a reception, a potluck supper, or eating a meal at a restaurant. However, outbreaks are increasingly being recognized that are more widespread, that affect persons in many different places, and that are spread out over several weeks. For example, a recent outbreak of salmonellosis was traced to persons eating a breakfast cereal produced at a factory in Minnesota, and marketed under several different brand names in many different states. No one county or state had very many cases and the cases did not know each other. The outbreak was recognized because it was caused by an unusual strain of Salmonella, and because state public health laboratories that type Salmonella strains noticed a sudden increase in this one rare strain. In another recent outbreak, a particular peanut snack food caused the same illness in Israel, Europe, and North America. Again, this was recognized as an increase in infections caused by a rare strain of Salmonella.

The vast majority of reported cases of foodborne illness are not part of recognized outbreaks, but occur as individual or "sporadic" cases. It may be that many of these cases are actually part of unrecognized widespread or diffuse outbreaks. Detecting and investigating such widespread outbreaks is a major challenge to our public health system. This is the reason that new and more sophisticated laboratory methods are being used at the Centers for Disease Control and Prevention (CDC) and in state public health department laboratories.

For more information about the onset, duration, and symptoms of foodborne illness, go to the FDA Bad Bug Book. It is available at: http://www.cfsan.fda.gov/~mow/app2.html

Source:
Centers for Disease Control and Prevention. 2004. Foodborne Illness Questions and Answers. Available on-line at:
www.cdc.gov/ncidod/dbmd/diseaseinfo/foodborneinfections_g.htm