Restaurant Outbreak Investigations, 2014–2016

For Public Health

At a glance

Learn about gaps we found in retail food safety practices from investigations of 2014-2016 outbreaks reported to our National Environmental Assessment Reporting System.

Wide shot of a restaurant with several people at different tables.

Key takeaways

Our review of more than 400 outbreaks revealed gaps in retail food safety practices and in how outbreaks are investigated.

  • Gaps in retail food safety practices: Contamination of food by sick food workers contributed to more than half of outbreaks with contributing factor data. However, most establishments with outbreaks lacked written policies for practices to keep food from being contaminated by workers.
  • Gaps in how outbreaks are investigated: Investigations that start within 24-48 hours are more likely to uncover important information about outbreak causes. However, about 1 in 10 investigations began more than 2 days after an outbreak was identified.

Protecting food from contamination by sick workers can help reduce outbreaks. Improving investigation practices can help investigators identify what is making people sick and how to stop the outbreak.

Why this is important

Most foodborne outbreaks occur in retail food establishments like restaurants. We need to know more about how retail establishment characteristics and food safety policies and practices relate to foodborne outbreaks. This information will help food safety programs develop effective approaches to prevent outbreaks.

What we learned

We studied 404 of these kinds of outbreaks reported to CDC's National Environmental Assessment Reporting System (NEARS) in 2014–2016. Our data showed:

  • Contamination of food by sick food workers contributed to more than half of outbreaks with contributing factor data.
  • Most establishments with outbreaks lacked written policies for practices to keep food from being contaminated by workers.
    • About a third did not have written policies on glove use.
    • About half did not have written policies about food workers working while sick.
  • Investigations that start within 24-48 hours are more likely to uncover important information about outbreak causes. However, about 1 in 10 investigations began more than 2 days after an outbreak was identified.

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.
Content Source
National Center for Environmental Health
About This Page
Published: May 15, 2024
Updated: August 20, 2026

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

Reviewed: August 20, 2026

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