Federal health officials are investigating an outbreak of E. coli O26:H11 infections linked to raw-milk cheese made by Sierra Nevada Graziers, a California dairy producer.

The Food and Drug Administration issued an outbreak advisory in September 2026, and the Centers for Disease Control and Prevention has opened its own investigation. Multiple illnesses across states have been connected to the company’s products, according to Food Safety News.

Officials are warning consumers not to eat the implicated raw-milk cheese and asking retailers to stop selling it. Raw-milk products bypass the pasteurisation process that kills harmful bacteria, and federal agencies have long warned they carry a higher risk of foodborne illness.

The outbreak comes as demand for raw dairy products has grown in some markets. Health authorities advise anyone with symptoms such as severe stomach cramps, diarrhoea or vomiting after eating the cheese to seek medical attention promptly.

Investigators are tracing how the contamination happened and whether other products from the same facility are affected. The company has not issued a public statement in the reporting seen so far. Consumers who bought the implicated cheese are advised to check the FDA advisory and throw it away.