Why Investigators Did or Did Not Do Environmental Assessments for Restaurant Outbreaks

Findings from CDC’s National Environmental Assessment Reporting System

Most foodborne outbreaks occur in retail food establishments like restaurants. We looked at 403 foodborne outbreaks reported to CDC’s National Environmental Assessment Reporting System (NEARS).

An environmental assessment is an important part of outbreak investigations. It can determine how and why germs got into the environment and spread to make people sick. An environmental assessment provides information that can stop ongoing outbreaks and prevent them in the future. But, health department investigators do not always conduct environmental assessments of outbreaks.

Female investigator is speaking with a chef in a kitchen.

Why Did Investigators Do an Environmental Assessment for Outbreaks?

Investigators did environmental assessments when

  • They knew or suspected the illness that caused the outbreak
  • Their health department had a policy to do these assessments
  • Their health department had the people and time available to do the assessment

Why Didn’t Investigators Do an Environmental Assessment for Outbreaks?

Investigators did not do environmental assessments when

  • Their health department lacked resources or training
  • The restaurant was not in their health department’s jurisdiction
  • Restaurant staff did not want to cooperate
  • Poor communication prevented timely responses

What’s Next

We are working to learn more about how retail establishment characteristics and food safety policies and practices relate to foodborne outbreaks. Our goal is to provide data to help food safety programs develop effective approaches to prevent outbreaks.


Local, state, tribal, and territorial programs use NEARS to report environmental assessment data. These data come from foodborne illness outbreak investigations in restaurants, banquet facilities, schools, and other institutions.

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