What Helps Investigators Find the Causes of Foodborne Outbreaks

More than 800 foodborne illness outbreaks happen in the United States every year. Data on their contributing factors are critical to preventing them, and those factors are identified through environmental assessments carried out by environmental health and food safety staff during an outbreak investigation. Less is known about what helps investigators find them, so CDC looked at which outbreak traits went along with success.

The data

The study used outbreak data reported to CDC's National Environmental Assessment Reporting System (NEARS). Local, state, tribal and territorial programs use NEARS to report environmental assessments from foodborne outbreak investigations in restaurants, banquet facilities, schools and other institutions.

What they found

Investigators identified contributing factors in 3 of every 5 outbreaks — 194 of 297. They were more likely to do so when:

• the germ behind the outbreak was known;
• the establishment prepared all its meals on-site;
• the establishment served more meals a day;
• investigators contacted the establishment quickly — within a day of learning about the outbreak — to schedule their visit;
• investigators made more than one visit to finish the assessment.

What investigators can do

• Let what is known about the germ guide the assessment.
• Start the assessment as soon as a possible outbreak comes to light.
• Make it complete, even if that takes several visits.

Timely, complete assessments are key, which is why strong environmental health and food safety programs with the capacity to do them matter. CDC also offers free, interactive online training in conducting environmental assessments.

Sources

Rewritten from the Centers for Disease Control and Prevention page "Data on Outbreak Contributing Factors" (public domain), a plain-language summary of a CDC journal article, in hubnx's own words.