Federal health officials are investigating a multistate outbreak of E. coli O157:H7 infection linked to raw cheddar cheese, according to a recent alert from the US Food and Drug Administration. Nine individuals have become ill, and three have been hospitalized, prompting renewed warnings about the dangers of raw milk and cheeses made from it.

Rising Demand vs. Public Health Concerns

Despite longstanding warnings from public health authorities, a growing number of consumers are seeking out raw milk for perceived health benefits. This creates tension regarding the safety of raw milk, who is most vulnerable, and what consumers should consider when choosing dairy products. CNN spoke with Dr. Leana Wen, an emergency physician and clinical associate professor at George Washington University, to address these concerns.

Understanding E. coli O157:H7

Dr. Wen explained that E. coli is a common group of bacteria, with many strains being harmless. However, certain strains, like E. coli O157:H7, can cause severe illness. This strain produces a toxin that damages the intestinal lining, leading to severe abdominal cramps and often bloody diarrhea.

In some cases, infection can lead to hemolytic uremic syndrome, a complication causing kidney failure and potentially death. This is particularly dangerous for children between 6 months and 4 years old.

Details of the Current Outbreak

The current outbreak, as reported by the FDA, is linked to raw, unpasteurized cheddar cheese. Between September 2025 and February 2026, nine people were infected with E. coli O157:H7 after consuming raw milk cheddar from a California-based company. Three were hospitalized, and one developed hemolytic uremic syndrome.

Over half of the illnesses occurred in children under 5 years old. The FDA has recommended a voluntary product recall, but the producer has declined. Outbreaks linked to raw milk and its products, including E. coli, salmonella, campylobacter, and listeria, are not uncommon.

How Infection Occurs

E. coli and other bacteria are naturally present in cattle intestines and the environment. During milking and processing, these bacteria can contaminate the milk if strict hygiene isn’t maintained. Pasteurization is designed to eliminate these pathogens.

Without pasteurization, any bacteria present remain in the final product. Even with careful farming practices, contamination can occur through manure, udder infections, improperly cleaned equipment, or human handling.

The Role of Pasteurization

Pasteurization involves heating milk to a specific temperature for a set time, then rapidly cooling it. In the US, milk is typically heated to at least 161°F for 15 seconds. This process kills harmful bacteria while preserving the milk’s nutritional value.

Developed by Louis Pasteur in the 19th century, pasteurization has been a highly effective public health intervention, significantly reducing foodborne illnesses from milk.

Is Raw Milk Safe? Who is at Risk?

Dr. Wen states that raw milk and raw milk cheese are not safe to consume due to the risk of bacterial contamination. While anyone can get sick, young children, older adults, pregnant women, and those with weakened immune systems are at higher risk of severe illness.

Addressing Health Claims

Claims about the health benefits of raw milk – such as containing beneficial bacteria or curing diseases – are not supported by scientific evidence. There is no clear evidence that raw milk offers health advantages over pasteurized milk, but consistent evidence shows increased risk of infection.

Key Takeaways

Consumers should understand that raw milk and its products can harbor dangerous bacteria. Choosing pasteurized dairy products is a simple way to reduce risk. Staying informed about outbreak alerts and avoiding recalled products is also crucial. Individuals experiencing severe abdominal pain, high fever, or bloody diarrhea after consuming potentially contaminated food should seek medical attention.