What is a Food Illness Outbreak?
When two or more people get the same illness from the same contaminated food or drink, the event is called a foodborne outbreak. Public Health officials investigate outbreaks to control them, so more people do not get sick in the outbreak, and to learn how to prevent similar outbreaks from happening in the future.
How Does Food Get Contaminated?
It takes several steps to get food from the farm or fishery to the dining table. Contamination can occur at any step in this process—during production.
| Steps | Definition | Examples of Contamination |
| Production | Growing the plants we harvest or raising the animals we use for food | If fields are sprayed with contaminated water, fruits and vegetables can be contaminated before harvest. |
| Processing | Changing plants or animals into what we recognize and buy as food. | If contaminated water or ice is used to wash, pack, or chill fruits or vegetables, the contamination can spread to those items. |
| Distribution | Moving food from the farm or production plant to the consumer or a kitchen. | If refrigerated food is left on a loading dock for long time in warm weather. It could reach temperatures that allow bacteria to grow. |
| Preparation | Getting the food ready to eat. This may occur in the kitchen of a restaurant, home, or institution. | If a cook uses a knife to cut raw chicken and then uses the same knife without washing it to slice tomatoes, the tomatoes can be contaminated by pathogens from the chicken. |
Who Responds to Outbreaks?
Local agencies: Most foodborne outbreaks are local events. Public health officials in just one city or county health department investigate these outbreaks.
State agencies: The state health department investigates outbreaks that spread across several cities and counties. This department often works with the state department of agriculture and with federal food safety agencies.
Centers for Disease Control and Prevention (CDC): For outbreaks that involve large numbers of people or severe or unusual illness, a state may ask for help from the Centers for Disease Control and Prevention (CDC). The CDC usually leads investigations of widespread outbreaks— those that may affect many states at once.
Federal Regulatory agencies: The CDC collaborates with the Food and Drug Administration (FDA), the USDA’s Food Safety and Inspection Service (FSIS), or the Environmental Protection Agency (EPA) throughout all phases of an outbreak investigation. In the case of an outbreak of foodborne illness, these federal agencies work to find out why it occurred, take steps to control it, and look for ways to prevent future outbreaks. They may trace foods to their origins, test foods, assess food safety measures in restaurants and food processing facilities, lead farm investigations, and announce food recalls.
Foodsafety.gov