Illnesses Associated with Unpasteurized Dairy Products

Indiana Epidemiology Newsletter
April 2007

Lynae Granzow, BS
Enteric Epidemiologist

Despite the risks of consuming unpasteurized dairy products and research indicating no meaningful difference in the nutritional values of pasteurized and unpasteurized milk, reported cases of illness related to unpasteurized dairy products still occur each year in Indiana. Consuming unpasteurized dairy products can lead to diseases such as listeriosis, salmonellosis, campylobacteriosis, brucellosis, typhoid fever, tuberculosis, and diphtheria. These infections can be especially severe in pregnant women and their unborn fetuses and can result in miscarriage, stillbirths, and birth defects. Complications can also include meningitis, sepsis, liver failure, and even death. Since 2001, there have been five reported disease outbreaks involving unpasteurized dairy products in the United States. These outbreaks have caused more than 200 people to become ill and five stillborn births, and have involved many states, including Indiana.

Two cases of unpasteurized dairy product exposures were reported the week of April 16, 2007, to the Indiana State Department of Heath (ISDH) Epidemiology Resource Center. These cases illustrate the need for education regarding the risks associated with consuming unpasteurized milk, especially for those at higher risk of illness (pregnant women, children, elderly, and those with weakened immune systems), as an important public health message.

Case one:

A 24-week pregnant woman was confirmed positive for campylobacteriosis. She reported drinking raw milk purchased from a farm on a regular basis. She has declined to release the name or location of the farm that sells the raw milk. She and her family drink the milk because of the "nutritional benefits” of raw milk and did not believe that the milk was the source of her infection.

Case two:

A 34-week pregnant Hispanic woman was confirmed positive for listeriosis. She was hospitalized in intensive care and underwent an emergency C-section. Fortunately, the infant was not infected. The woman is still under direct medical care and receiving a two-week course of intravenous antibiotics. She reported daily consumption of unpasteurized queso fresco that was purchased from a local vendor that visits her community on Saturdays. Although none of the cheese she consumed was available for testing, some of the cheese that the family currently had from the same vendor was collected for testing. The results were negative for Listeria, however, coliforms were TNC and Staph aureus was > 7,000 cfu.

The ISDH and the Board of Animal Health (BOAH) are collaborating on these investigations. The sale of raw milk for human consumption is illegal in Indiana, although raw milk can be purchased legally from a farm that will be pasteurizing the milk or using it for animal feed. In either case, the milk must be collected in bulk tanks. Individuals cannot purchase small amounts, e.g., one or two gallons of milk, at a time.

Cow-sharing or cow-leasing is a process in which persons purchase a "portion" of a cow and provide fees for boarding. Persons then take raw milk from the cow without actually “purchasing” the milk from the farmer. According to the BOAH, Indiana law (IC 15-2.1-23-8; IC 15-2.1-23-8.5) states that a person may not offer, sell, or deliver raw dairy products, which would include cow shares.

Although raw milk cheese can be sold in Indiana under regulation, consumers should buy food products from inspected, licensed sources only. Do not assume that any cheese is safe unless it is clearly labeled with the manufacturer’s/distributor’s name and address or facility code, date of manufacture, and a statement that the cheese has been cured or ripened for at least 60 days.

Education is also important regarding the risk of illness from consuming raw milk cheeses, such as queso fresco, and the potential dangers of infection.