Health officials in Idaho are investigating a multi-county outbreak of Campylobacter infections linked to the consumption of raw, unpasteurized milk, with at least 60 illnesses identified to date.
According to the Idaho Department of Health and Welfare, at least 45 patients have tested positive for campylobacteriosis, while all 60 affected individuals reported consuming raw milk before becoming ill.
State health officials have traced the outbreak to two dairies—one located in northern Idaho and the other in southern Idaho. The names of the dairies have not yet been released as investigators continue their work.
The first illness associated with the outbreak was reported on May 19, 2026. Officials are continuing to interview patients and conduct epidemiological investigations, and additional cases may still be identified.
Investigators are working to determine whether specific batches of raw milk are responsible for the illnesses and are testing milk samples for contamination. Both dairies are cooperating with state and local health authorities to identify and address potential sources of contamination.
The Idaho Division of Public Health is collaborating with several regional health agencies, including Panhandle District Health, Southwest District Health, Central District Health, Southeastern Idaho Public Health, South Central Public Health, and Eastern Idaho Public Health.
Campylobacter is a bacterium that can cause gastrointestinal illness, leading to symptoms such as diarrhea, abdominal cramps, fever, nausea, and vomiting. In some cases, infections can result in severe complications, particularly among vulnerable populations.
Health officials continue to warn consumers about the risks associated with consuming raw, unpasteurized dairy products.
“Raw, unpasteurized dairy products can contain bacteria that make people sick, particularly young children, pregnant women, older adults, and individuals with weakened immune systems,” the Idaho Department of Health and Welfare stated.
Public health experts emphasize that pasteurization effectively eliminates harmful pathogens while maintaining the nutritional value of milk. The process involves heating milk to 161°F (72°C) for 15 seconds, destroying bacteria such as Campylobacter, Salmonella, Escherichia coli (E. coli), and Listeria monocytogenes.
Research from the University of Delaware has shown that people who consume raw milk are significantly more likely to experience foodborne illness than those who consume pasteurized dairy products. According to the study, raw milk consumers are 840 times more likely to become ill and 45 times more likely to require hospitalization.
Health authorities advise consumers to avoid drinking raw milk and consuming products made from unpasteurized milk, particularly those in high-risk groups. Anyone experiencing symptoms consistent with Campylobacter infection after consuming raw dairy products should seek medical attention and inform healthcare providers about their exposure.