2021 Outbreak of Listeria Infections Linked to Packaged Salads Produced by Fresh Express – Investigation Details
CDC, public health and regulatory officials in several states, and the U.S. Food and Drug Administration (FDA) investigated a multistate outbreak of Listeria monocytogenes infections.
Epidemiologic and laboratory data showed that packaged salads produced by Fresh Express were contaminated with Listeria and made people sick.
As of March 8, 2022, this outbreak is over.
Epidemiologic Data
A total of 10 people infected with the outbreak strain of Listeria monocytogenes were reported from eight states (see map). The true number of sick people in this outbreak is likely higher than the number reported, and the outbreak may not have been limited to the states with known illnesses. This is because some people recover without medical care and are not tested for Listeria.
Illnesses started on dates ranging from July 26, 2016, to October 19, 2021 (see timeline). Sick people ranged in age from 44 to 95 years, with a median age of 80, and 60% were female. All 10 people were hospitalized. One death was reported from Pennsylvania.
State and local public health officials interviewed people (or their family) about the foods they ate in the month before they got sick. Of the five people interviewed, four (80%) reported eating packaged salads of various types and two specifically reported eating Fresh Express brand salads.
Laboratory Data
Public health investigators used the PulseNet system to identify illnesses that were 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.
On December 16, 2021, the Michigan Department of Agriculture & Rural Development identified the outbreak strain of Listeria in a bag of Fresh Express Sweet Hearts packaged salad collected from a grocery store during routine sampling. The packaged salad was produced at the Fresh Express facility in Streamwood, Illinois.
Public Health Actions
On December 20, 2021, Fresh Express recalled packaged salads produced at its facility in Streamwood, Illinois.
CDC, public health and regulatory officials in several states, and the U.S. Food and Drug Administration (FDA) are collecting different types of data to investigate a multistate outbreak of Listeria monocytogenes infections.
Epidemiologic and laboratory data show that Fresh Express packaged salads may be contaminated with Listeria and may be making people sick.
Epidemiologic Data
As of December 21, 10 people infected with the outbreak strain of Listeria monocytogenes have been reported from eight states (see map). Illnesses started on dates ranging from July 26, 2016 through October 19, 2021 (see timeline).
Sick people range in age from 44 to 95 years, with a median age of 80, and 60% are female. All 10 people have been hospitalized. One death has been reported from Pennsylvania.
The true number of sick people in an outbreak is likely higher than the number reported, and the outbreak may not be limited to the states with known illnesses. This is because many people recover without medical care and are not tested for Listeria.
State and local public health officials are interviewing people about the foods they ate in the month before they got sick. Of the five people interviewed, four (80%) reported eating packaged salads of various types. Two ill people specifically reported eating Fresh Express brand salads. Investigators are working to get more information about the brands and types of packaged salads eaten by sick people.
Laboratory Data
Public health investigators are using 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 are closely related genetically. This means that people in this outbreak likely got sick from the same food.
On December 16, 2021, the Michigan Department of Agriculture identified the outbreak strain of Listeria in a bag of Fresh Express Sweet Hearts Romaine Lettuce Sweet Butter Lettuce packaged salad collected from a grocery store during routine sampling.
Public Health Actions
On December 20, 2021, Fresh Express recalled packaged salads produced at its facility in Streamwood, Illinois, since November 20, 2021. Do not eat, sell, or serve recalled salads. CDC and FDA are working to determine if additional products are contaminated.
