number of Minnesotans sickened with Salmonella poisoning after eating unpasteurized, homemade queso fresco – a Mexican-style cheese – more than doubled before the outbreak ran its course. Health officials said Monday that the number of illnesses in the outbreak have reached 25, up from the 12 cases originally reported two weeks ago. They said the outbreak illustrates the dangers of consuming unpasteurized dairy products.The Minnesota Department of Health (MDH), the Minnesota Department of Agriculture (MDA) and the City of Minneapolis have been investigating the outbreak and the source of the raw milk used to make the cheese since the first cases were detected in late April.
MDH confirmed 18 cases of infection with the same strain of Salmonella. An additional seven cases of illness occurred among family members or other contacts of confirmed cases, but no laboratory specimens were available. The individuals fell ill between March 28 and April 24. Of the 25 people sickened, 15 were hospitalized.
All have since recovered. Many patients reported eating unpasteurized queso fresco purchased or received from an individual who made the product in a private home.
Investigators have determined that the individual made home deliveries and also may have sold the product on a street corner near the East Lake Street area of Minneapolis.
The local health officials says anyone who may have purchased or received this product recently should not eat it but should throw it away.
Samples of unpasteurized queso fresco collected from the cheese maker were found to contain the same strain of Salmonella as the illnesses. Investigators determined that the milk used to make the cheese was purchased by the cheese maker from a Dakota County farm. Unpasteurized milk samples collected at the farm were also found to match the outbreak strain.
Dr. Heidi Kassenborg, director of MDA’s Dairy and Food Inspection Division, said: “It only takes a few bacteria to cause illness. Milking a cow is not a sterile process and even the cleanest dairy farms can have milk that is contaminated. That’s why pasteurization – or the heat treatment of milk to kill the harmful pathogens – is so important.”
Minnesota law allows consumers to purchase raw milk products directly from the farm for their own consumption, but they may not be further distributed or sold. Additionally, cheese production facilities need to follow proper food safety laws and regulations, including licensure.
Dr. Carlota Medus, foodborne illness epidemiologist, said the outbreak may be over, as there are no suspect cases pending. However, it is still possible that investigators will learn of additional cases that have not yet been reported from people who consumed cheese prior to health officials’ interventions, which occurred April 23-26.
Health officials are also concerned that this may not be an isolated incident – that there may be other instances of people buying foods like unpasteurized queso fresco prepared by neighbors, friends or family.
“It’s important for people to be aware of the inherent risk of consuming any raw dairy product from any source,” Medus said. “We encourage people to think carefully about those risks and know that the risks are especially high for young children, pregnant women, the elderly and those with weakened immune systems.”
Salmonella bacteria can cause serious and sometimes fatal infections, especially in high-risk groups. Healthy people infected with Salmonella generally experience diarrhea, fever, and abdominal pain. Symptoms normally begin between 12 and 72 hours after consumption of contaminated food but can begin up to a week or more later.
Anyone who believes they may have become ill with a Salmonella infection should contact their health care provider.
