Foodborne Disease Outbreaks


A foodborne disease outbreak is defined as two or more illnesses caused by the same germ (e.g., a toxin, virus or bacteria) which are linked to eating the same food. The Centers for Disease Control and Prevention (CDC) estimates that each year roughly 1 in 6 Americans (or 48 million people) get sick, 128,000 are hospitalized, and 3,000 die of foodborne diseases. Only a small percentage of those are related to a foodborne disease outbreak. Additionally, it is thought that the number of foodborne illnesses reported to the health department is much less than the actual number of illnesses that occur every year.

Foodborne disease outbreaks can occur in a variety of settings including, but not limited to:

  • A restaurant meal
  • A church potluck
  • A catered meal
  • A festival or temporary food event

If a foodborne disease outbreak occurs after a specific event (such as the events listed above), the local health department in that area (where the event was held) would be responsible for investigating the outbreak. Foodborne disease outbreaks can also involve residents from different areas across one state or from several states, such as when a contaminated food item has been distributed regionally or nationally. These types of outbreaks can be more difficult to identify and investigate, as multiple agencies and jurisdictions may be required to participate in the outbreak investigation.

Foodborne disease outbreaks can have significant, long-term economic and health impacts. It is important to report any potential foodborne disease outbreak to your local health department as soon as possible.

In the event of a suspected foodborne disease outbreak, the role of the health department is to:

  • Confirm that an outbreak has occurred
  • Identify the germ causing people to become sick
  • Identify the source of the outbreak (e.g., the contaminated food item)
  • Control the spread of illness
  • Prevent future illnesses

Foodborne disease outbreak investigations require a team effort. This partnership can include the Virginia Department of Health (VDH), physicians, laboratories, regulatory agencies, and the public. The public is a vital member of the team in that they are often the first to become aware an outbreak has occurred, and they may possess information that can help identify why the outbreak happened and how it can be stopped.

Steps to a Foodborne Illness Outbreak Investigation

Within the local health department, a multidisciplinary approach is necessary for investigating a foodborne disease outbreak. Many health districts have a response team structure in place to allow for a prompt and appropriate response when and if foodborne disease outbreaks occur in their district. Generally speaking this health department response team structure includes:

  • Health Director
  • Epidemiology/Nursing
  • Environmental Health
  • Other district staff in supportive roles
  • VDH Central Office in Richmond (for guidance and consultation, as appropriate)

Below are the general steps of a foodborne disease outbreak investigation. Information provided by the public through phone calls, illness reports, or follow-up investigations can be key to solving an outbreak.

1. Information Gathering

  • Initial report: We want to gather as much information as we can while it is fresh in your mind. This is especially important when it comes to providing a detailed food history.
  • Interviews: Comprehensive interviews of both sick and healthy people are done to identify what may have made people ill.
  • Sampling: Food samples and human specimens may be taken to determine if the same germ is present in both. It is important to collect these samples as early as possible!
  • Inspections: If multiple illnesses are linked to a common location, an inspection may be conducted by a VDH Environmental Health Specialist or a Virginia Department of Agriculture and Consumer Services (VDACS) inspector. These inspections will examine how the food could have been contaminated, observe the establishment for problems in hygienic practices, and evaluate the risk factors that pose the biggest risk to the public.Location to Hospital

2. Organize and analyze data

The investigative team will examine the findings from lab results, inspection reports, and foodborne illness complaints to determine what may have occurred to make people sick.1 out of 6

3. Recommend control and surveillance methods

The investigative team will determine how future illnesses can be prevented, and will recommend steps to keep people healthy. If the outbreak occurs at a restaurant, this could be as simple as fixing any identified problems on the spot or providing detailed training to restaurant staff. The Local Health Department will decide how to properly monitor restaurant operations until all issues have been corrected.Breakfast

4. Document investigation findings

Once all of the information has been gathered and the investigation is complete, the investigative team will create a detailed report of the findings. This information will be sent to the CDC for national reporting and will be included in VDH’s annual outbreak report data.Follow Up