Following potential exposure to bacteria from unpasteurized milk sold at a farmers’ market in Missoula County, the Missoula City-County Health Department is warning residents of the dangers of consuming unpasteurized, or “raw,” milk.
Milk that was recently sold at a local farmers market came from a herd where two cows tested positive for Coxiella burnetii, which is the bacteria that causes Q fever. While one of those cows had not yet produced milk, the other produced about 10% of the farmer’s yield.
“We don’t know if the cow was shedding the bacteria at the time it was milked, or if that cow’s milk was sold at the farmers market,” said Environmental Health Director Shannon Therriault. “So, we can’t say for sure whether anyone was exposed. However, what we do know is that unpasteurized milk can contain harmful bacteria that can make you and your loved ones sick.”
Unpasteurized milk products have been linked to outbreaks of E. coli, campylobacter, salmonella, brucella, listeria and cryptosporidium. In the case of Q fever, symptoms can take two or three weeks to present following exposure. According to the Centers for Disease Control and Prevention, symptoms of Q fever include fever, chills, fatigue, headache, muscle aches, nausea, vomiting, diarrhea, chest pain, stomach pain, weight loss and a non-productive cough.
“While drinking ‘raw’ milk has become more widespread in recent years, we want people to know that it can easily be contaminated with harmful bacteria, even when the milking operation is well-run,” Therriault said.
In the 1980s, Missoula experienced a large salmonella outbreak caused by unpasteurized milk from a local dairy. More than 100 cases were linked to the outbreak, and half of those cases were children 14 and younger. The strain of salmonella was multi-drug resistant, and 15% of those who got sick were hospitalized. An inspection of the dairy revealed no sanitation laws or practices on the books at that time were broken.
After that outbreak, Montana passed a law that all milk sold to consumers had to be pasteurized. The CDC reports that when milk pasteurization requirements began in the early 1990s, deaths and diarrheal illnesses in young children declined dramatically. In 2021, the legislature reversed course, and unpasteurized milk sales are now allowed in Montana under certain, limited conditions. Unpasteurized milk can be sold at a farm, farmers markets and other traditional community events, if the herd is five lactating cows or fewer, and the seller informs the end consumer that the product is not licensed, certified, packaged, labeled or inspected under any official regulations.