Dec 23, 2020

FDA links fall E. coli outbreak to leafy greens

The FDA and Centers for Disease Control (CDC) in collaboration with state and local partners, have completed the investigation on two of three multi-state outbreak of E. coli O157:H7 infections in the U.S. this fall.

According to a news release, one of these investigations, Outbreak Unknown Source 3, identified 18 reported illnesses in nine states: California, Colorado, Illinois, Michigan, New York, Ohio, Pennsylvania, Virginia, Washington.

FDA completed a traceback investigation of several potential food vehicles identified in patient interviews and although no single farm was identified as a common source of the outbreak, FDA and state partners also conducted on-site investigations on farms of interest.

However, information and samples collected in these inspections did not link these farms to the outbreak.

The investigation of a farm does not mean that the farm is linked to an outbreak. The results of an investigation into a farm may well lead to that firm being ruled out of the investigation. On Dec. 18, 2020, the CDC announced that this outbreak had ended.

The other completed outbreak investigation, Outbreak Unknown Source 1, identified 32 reported illnesses in 12 states: California, Illinois, Louisiana, Maryland, Michigan, Montana, New Jersey, Ohio, Utah, Virginia, Washington, Wisconsin.

This strain of E. coli is genetically similar to a strain linked to a romaine outbreak that occurred in the spring of 2018, though a food was not linked to the current outbreak.

FDA completed a traceback investigation and was unable to determine a common source of the outbreak. FDA and state partners also conducted on-site inspections on farms of interest, though information collected in these inspections did not link these farms to the outbreak.

On Dec. 12, 2020, the CDC announced that this outbreak had ended.

Investigations of a third E. coli outbreak of Unknown Source 2 continue.

The FDA, along with CDC and state and local partners, investigated a multi-state outbreak of E. coli O157:H7 infections in the fall of 2020. The epidemiology and traceback investigation have determined that the outbreak was linked to leafy greens.

The epidemiological and traceback investigations were not able to determine a specific type of leafy green linked to illnesses. On Dec. 22, 2020, the CDC announced that this outbreak appears to be over.

This outbreak, announced by FDA and CDC on Oct. 28, 2020, was caused by a strain of E. coli that is genetically related to a strain linked to the fall 2019 romaine outbreak.

The FDA completed a traceback investigation of multiple types of leafy greens identified in patient interviews. Although no single ranch was identified as a common source of the leafy greens, FDA and state partners also conducted on-site investigations on farms of interest.

Teams were deployed to dozens of ranches in the region to conduct large scale environmental sampling. Additionally, no Shiga toxin-producing E. coli were found on leafy greens.

At this time, FDA’s investigational activities, including sample analysis are ongoing. A detailed report of FDA’s findings in the investigation will be released in early 2021, following the conclusion of investigational activities.

Recommendation

CDC has declared this outbreak to be over. There is no recommendation for consumers, retailers, or suppliers.

Case Counts
Total Illnesses: 40
Hospitalizations: 20 (4 Cases HUS)
Deaths: 0
Last Illness Onset Date: October 31, 2020
States with Cases: AZ (2), CA (6), IL (2), IN (1), KS (4), MI (3), MN (2), MO (3), ND (4), OH (1), OR (1), PA (2), TN (2), TX (1), UT (1), VA (1), WA (1), WI (2), WY (1)
*States with confirmed distribution; product could have been distributed further.