Environmental Assessments of Foodborne Outbreaks: Key Terms

When a foodborne outbreak happens, an environmental assessment works out how and why germs got into the environment and spread to make people sick, and so can reveal the outbreak's root causes. Participating health departments report assessment data on restaurants and other retail food service establishments to CDC's National Environmental Assessment Reporting System (NEARS).

The terms

Foodborne illness outbreak. Two or more people get sick after eating the same food.

Contributing factors. What happened to cause an outbreak: how it came about.

Environmental antecedents. Why the contributing factors happened, sometimes called the outbreak's root causes. For example, the main contributing factor in a norovirus outbreak might be a food worker who worked while sick. The antecedents are the reasons behind that, such as:

• the worker would not have been paid for staying home;
• a manager insisted the worker come in because no one else could cover the shift.

Environment. Everything outside the host, the infected person:

• food, including acidity, pH and other properties that affect whether pathogens survive and grow;
• water, such as contaminated ice;
• other people, such as a worker handling food while sick;
• the built environment, such as how a kitchen is designed.

Farm-to-fork continuum. The path food takes from its source to where it is finally served:

1. source, where it originates;
2. processing and manufacturing, the steps that prepare it for distribution;
3. distribution, storage, warehousing, repacking, reprocessing and transport;
4. point of final service, anywhere food is bought or eaten, such as delis, cafeterias, restaurants and grocery stores.

Food safety system. Every step along the continuum, and each step is also a food safety system of its own. All have the same parts:

System theory. Looking at the whole system and how all its forces interact, rather than at one part in isolation.

Interventions (science-based). Actions to stop an outbreak and prevent others, based on the environmental assessment and the rest of the investigation.

• Immediate: destroying unsafe food or stopping its distribution; keeping sick food workers from working; closing the facility.
• Longer term: developing and carrying out a Hazard Analysis Critical Control Point (HACCP) plan; setting and enforcing policies for identifying and managing workers sick with diarrhea, vomiting or fever.

Sources

• CDC, "Environmental Assessment Definitions": https://www.cdc.gov/restaurant-food-safety/php/investigations/ea-definitions.html
• CDC, contributing factors, root causes, NEARS and system theory: https://www.cdc.gov/restaurant-food-safety/php/investigations/factors.html, https://www.cdc.gov/restaurant-food-safety/php/investigations/root-causes.html, https://www.cdc.gov/restaurant-food-safety/php/investigations/nears.html, https://www.cdc.gov/restaurant-food-safety/php/training/system-theory.html