Successful Outbreak Investigations

For Public Health

At a glance

Foodborne outbreak investigations are successful more often when they include data collected through epidemiologic investigation, laboratory testing, and environmental health assessment.

graphic of epidemiologists, a laboratorian, and a public health investigator.

Key takeaways

Successful outbreak investigations identify the food item(s), germ(s), and contributing factors of the outbreak. Identifying these data points can help stop the current outbreak and prevent more in the future.

Why this is important

This study adds to evidence showing the importance of a unified public health response during a foodborne outbreak investigation that includes epidemiologists, laboratorians, and environmental health professionals. The results of this study can help guide state and local health departments when investigating a foodborne illness outbreak.

What we learned

We analyzed data from outbreaks reported to our National Environmental Assessment Reporting System (NEARS). The analysis revealed that successful investigations occur more often when investigators do these activities:

  • Use robust epidemiology investigation techniques, such as a cohort study, to identify the food associated with the outbreak and people who got sick
  • Collect and test clinical samples from people who got sick to identify what made people sick
  • Conduct a thorough environmental assessment of the outbreak environment to identify root causes and factors that led to the outbreak
Epidemiology
  • Epidemiologists conduct activities such as interviewing the people who got sick (hosts) to determine their symptoms and what foods they recently ate.
  • Answers the questions: Who got sick and where? What foods did they eat?

Laboratory

  • Laboratorians test clinical samples, or stool samples, from hosts to determine what is making people sick (agent).
  • Answers the question: What is making people sick?

    • Environmental health

  • Environmental health specialists conduct environmental assessments of the outbreak establishment’s kitchen (environment) and other activities to understand factors that contributed to the outbreak.
  • Answers the question: How and why are people getting sick?

    • More information

    About this study

    This study assessed outbreak data reported to the National Environmental Assessment Reporting System (NEARS). 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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    Content Source
    National Center for Environmental Health
    About This Page
    Published: May 15, 2024
    Updated: April 21, 2024

    This page was last updated on this date. Updates may include minor edits, image changes, or other modifications to page content.

    Reviewed: August 25, 2026

    The information on this page was last reviewed by subject matter experts to ensure accuracy.