Investigation Update: E. coli Outbreak, Organic Carrots, November 2024

CDC, public health and regulatory officials in several states, and the U.S. Food and Drug Administration (FDA) collected different types of data to investigate a multistate outbreak of E. coli O121 infections.

Epidemiologic and traceback data showed that organic carrots supplied by Grimmway Farms were likely contaminated with E. coli and made people sick.

Epidemiologic data

A total of 48 people infected with the outbreak strain of E. coli were reported from 19 states. Illnesses started on dates ranging from September 6, 2024, to November 10, 2024. Of 47 people with information available, 20 were hospitalized and one developed hemolytic uremic syndrome, a serious condition that can cause kidney failure. One death was reported from California.

The true number of sick people in this outbreak was likely much higher than the number reported, and the outbreak may not have been limited to the states with known illnesses. This is because many people recover without medical care and are not tested for E. coli.

Public health officials collect many different types of information from sick people, including their age, race, ethnicity, other demographics, and the foods they ate in the week before they got sick. This information provides clues to help investigators identify the source of the outbreak.

The table below has information about sick people in this outbreak ("n" is the number of people with information available for each demographic).

State and local public health officials interviewed people about the foods they ate in the week before they got sick. Of the 37 people interviewed, 33 (89%) reported eating carrots. This percentage was significantly higher than the 63% of respondents who reported eating carrots in the FoodNet Population Survey—a survey that helps estimate how often people eat various foods linked to diarrheal illness. This difference suggests that people in this outbreak got sick from eating carrots.

Laboratory and traceback information

Public health investigators used the PulseNet system to identify illnesses that may be part of this outbreak. CDC PulseNet manages a national database of DNA fingerprints of bacteria that cause foodborne illnesses. DNA fingerprinting is performed on bacteria using a method called whole genome sequencing (WGS).

WGS showed that bacteria from sick people's samples were closely related genetically. This suggests that people in this outbreak got sick from the same food. WGS analysis of bacteria from 45 people's samples did not predict resistance to any antibiotics. More information is available at the National Antimicrobial Resistance Monitoring System (NARMS) site. These findings do not affect treatment guidance since antibiotics are not recommended for patients with Shiga toxin-producing E. coli (STEC) infections.

People reported buying different brands of carrots from multiple stores. FDA's traceback of some of these purchases identified Grimmway Farms as the common supplier of organic whole and baby carrots in this outbreak. FDA conducted inspections at Grimmway Farms and collected environmental samples. Two environmental samples collected outside were positive for STEC. Although both strains of E. coli detected in the samples are capable of causing human illness, neither match the strain of E. coli causing illnesses in this outbreak. The strain of E. coli causing illnesses in this outbreak was not found in environmental samples; however, epidemiologic and traceback evidence shows that recalled carrots were the likely source of illnesses in this outbreak.

Public health actions

This outbreak is over. These products are no longer in stores and are past shelf life. However, they may be in your refrigerator or freezer. Check your freezer for any recalled products and throw them away or return them to where you bought them. Always take steps to protect yourself from getting sick from E. coli.

On November 16, 2024, Grimmway Farms initiated a voluntary recall of these carrots and contacted their distributors. On November 21, 2024, the recall expanded to include additional bag sizes for organic whole carrots. Additional recalls were conducted by companies that used or repackaged carrots that may have come from Grimmway Farms.