Investigation Update: E. coli Outbreak, September 2026

CDC, the U.S. Food and Drug Administration (FDA), and public health and regulatory officials in several states are collecting different types of data to investigate a multistate outbreak of E. coli O26 infections.

Epidemiologic data show that Sierra Nevada Cheese Company Graziers raw milk cheese may be contaminated with E. coli and making people sick.

Epidemiologic Data

Cases

Illnesses started on dates ranging from July 7, 2026, to August 26, 2026. The true number of sick people in this outbreak is likely much 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 E. coli. In addition, recent illnesses may not yet be reported as it usually takes 3 to 4 weeks to determine if a sick person is part of an outbreak.

Demographics

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).

Foods consumed

State and local public health officials are interviewing people about the foods they ate in the week before they got sick. Of the 9 people interviewed, 9 (100%) reported eating Sierra Nevada Cheese Company's Graziers raw milk cheese. This percentage is significantly higher than the 4.9% of respondents who reported eating unpasteurized (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 suggests that people in this outbreak got sick from eating raw milk cheese.

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 suggests that people in this outbreak got sick from the same food.

Public Health actions

Do not eat recalled Graziers raw milk cheeses produced by Sierra Nevada Cheese Company. These products have a long shelf life.