Public Communication during Foodborne Outbreaks

Illustration of a news reporter on TV talking about an outbreak.

Warning consumers quickly about a contaminated food can save lives.

Public health and regulatory officials work quickly to find the source of foodborne disease outbreaks so they can take action to prevent more people from getting sick.

One of the most important actions public health officials can take to prevent illness is warning consumers quickly about a contaminated food. But first, they must identify the food. To do this, they collect three types of data: epidemiologic, traceback, and food and environmental tests. Health officials assess all of these data to try to find the likely source of the outbreak. They take action when there is clear and convincing information linking illness to a contaminated food that might continue to make people sick.

Deciding to Communicate

Multistate foodborne outbreak investigations are complex and involve many partners at local, state, and federal health and regulatory agencies. CDC usually leads outbreak investigations that involve more than one state. However, CDC makes the decision to communicate about a multistate outbreak with input from all of these partners.

CDC follows a consistent process for evaluating the need to warn consumers about ongoing multistate foodborne outbreaks. The process includes considering why communication might be needed. Rather than designing a rigid communication policy, CDC and investigation partners developed a flexible and comprehensive guide on when, what, and how to communicate during an outbreak.

CDC is most likely to warn consumers when the investigation identifies a specific food linked to illness, and there is a continuing risk to the public because the food is still in stores, restaurants, or homes. A company also may have recalled the contaminated food that was making people sick and CDC will share the recall information with the public. In this situation, there are specific, clear, and actionable steps for consumers to take to protect themselves from contaminated food.

When deciding to warn consumers, CDC considers whether:

  • Illnesses continue to be reported (an outbreak is ongoing)
  • The contaminated food is still available for sale or in people’s homes
  • The investigation has identified a specific brand or type of food linked to illness
  • The number of new illnesses is increasing rapidly
  • The illnesses are severe
  • A large number of people are sick who are more likely to get a severe illness
  • The outbreak strain is resistant to antibiotics that are used to treat illness

Informing the Public

If the decision is made to notify the public of an outbreak, CDC announces the outbreak using either a Food Safety Alert or an Investigation Notice. These announcements tell people what they can do to protect their health.

Food Safety Alerts provide urgent, specific advice to consumers, restaurants, and retailers about foods to avoid eating or selling. This advice may include information about a recall or other warnings.

Investigation Notices provide information about an outbreak not yet linked to a source, or an outbreak linked to a general type or category of food, rather than a specific food.

Both types of outbreak announcements typically include:

  • How many people are sick in each state
  • Signs and symptoms of the illness
  • Advice to consumers and retailers
  • Other investigation details, including food testing results, if available

CDC posts updates during outbreak investigations to ensure the website reflects the most accurate and current information. Updates are posted as needed, and the timing differs depending on the outbreak.

CDC posts a final update once an investigation ends.

Web announcements and updates are posted on the CDC Foodborne Outbreaks website. This website provides information about foodborne outbreaks where CDC was leading the epidemiologic investigation. State and local health department websites often provide information on local foodborne outbreaks they investigated, where CDC was not leading the investigation.

CDC also notifies the public through the following social media channels when a foodborne outbreak is announced or when new information is released:

Outbreak Reports and Publications

Public health officials don’t solve every outbreak. Sometimes the outbreak ends before enough information is available to identify the likely source and warn the public. The source also may be identified after the outbreak ends and the risk to the public is over because the food items are no longer available.

Even if an urgent warning is no longer needed, CDC often writes outbreak reports after an investigation ends. Health and regulatory officials continue monitoring an outbreak strain after an outbreak ends by looking for any new illness and studying the pathogen. Outbreak reports provide valuable information for people interested in food safety topics, such as the media, food safety educators, and consumer advocacy groups, as well as for food industries and regulatory officials as they work to make our food safer.

The CDC website also contains information on local, state, and national foodborne outbreaks reported to the National Outbreak Reporting System (NORS) since 1998. Any multistate foodborne disease outbreak that CDC investigates is reported to NORS. The NORS Dashboard is a publicly available, online tool that displays information from this reporting system. NORS Dashboard users can search outbreak data, see information displayed on interactive maps and graphs, download data, and more.