A total of 11 people infected with the outbreak strain of E. coli were reported from 5 states. Illnesses started on dates ranging from October 18, 2023, to February 5, 2024. Of 11 people with information available, 5 were hospitalized and 2 developed hemolytic uremic syndrome, a serious condition that can cause kidney failure. No deaths were reported.
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.
State and local public health officials interviewed people about the foods they ate in the week before they got sick. Of the 10 people interviewed, 7 (70%) specifically reported eating Raw Farm brand raw cheddar cheese. This percentage was significantly higher than the 4.9% of respondents who reported eating any raw milk cheese in the FoodNet Population Survey—a survey that helps estimate how often people eat various foods linked to diarrheal illness. This difference suggested that people in this outbreak got sick from eating Raw Farm brand raw cheddar cheese.
Public health investigators used the PulseNet system to identify illnesses that may have been 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 all sick people’s samples were closely related genetically. This suggested that people in this outbreak got sick from the same food.