On September 15, 2017, the CDC and Texas health officials warned people who consumed raw milk or raw milk products from one Texas dairy to contact their health care provider immediately. Investigators from the CDC and the Texas Department of State Health Services (DSHS) found that raw milk from the K-Bar Dairy in Paradise, Texas, (northwest of Fort Worth) tested positive for a rare but potentially serious bacteria known as Brucella RB51. The CDC advised that people who consumed raw milk or milk products from the K-Bar Dairy between June 1 and August 7, 2017, should get antibiotic treatment to avoid the risk of lifelong, chronic infections.
Brucella, a genus of Gram-negative bacteria, is the cause of brucellosis, which is a zoonosis transmitted by ingesting contaminated food (such as unpasteurized milk products), direct contact with an infected animal, or inhalation of aerosols. Initially, people with brucellosis experience fever, sweats, aches, and fatigue. If not treated, Brucella RB51 infection can result in long-term complications, like arthritis; heart problems; enlargement of the spleen or liver; and, in rare cases, nervous system problems, like meningitis. Brucella RB51 can cause severe illness in people with weakened immune systems and miscarriages in pregnant women. RB51 is resistant to some antibiotics that would normally be used to prevent or treat brucellosis.
People who have consumed the milk should also check themselves for fever for four weeks after last drinking the milk and watch for other brucellosis symptoms for six months. These symptoms include, but are not limited to: muscle pain, lasting fatigue, arthritis, depression, and swelling of the testicles.
Brucella is rare in the United States, largely due to vaccination practices in cattle to prevent brucellosis. There are approximately 120 reported cases in people each year. Most cases of brucellosis in the U.S. occur in people who traveled to countries where Brucella is more common and drank contaminated cow, sheep, or goat milk or had contact with infected animals. Among cases in the U.S. in which brucellosis was acquired here, infections occur from contact with feral swine or, more rarely, dogs, or because of accidental exposure in lab settings.
“It’s very important for people who drank raw milk from this dairy to seek treatment to prevent infection with Brucella RB51,” said William Bower, M.D., the team lead for the CDC group that investigates brucellosis. “Even if people don’t have any symptoms now, they can develop a chronic infection that can impact their health for years to come.”
Milk from K-Bar dairy is known to have caused Brucella infection in one Texas resident. Purchase records and illness reports indicate additional people in Texas and some as far away as California and North Dakota may need antibiotics to prevent or treat infection. In Texas, raw milk is only allowed to be sold on site at the dairy. According to Texas DSHS, K-Bar dairy has been operating in compliance with state dairy laws and rules and is cooperating fully with the investigation.
The CDC and Texas health officials have been trying to reach people in more than 800 households known to have purchased K-Bar raw milk. Texas is following up with 170. The CDC tried to contact the remaining 672 households, but many did not provide contact information. Of the 485 households with contact information, the CDC successfully reached 236 households. Among the 236 households, 83 percent of people were exposed to RB51 by drinking the milk. People who sampled the milk at the dairy or got the milk from friends or family also may not be aware of their risk. So far, people in Alabama, Arkansas, California, Ohio, North Dakota, Tennessee, and Texas who drank K-Bar milk have reported symptoms consistent with brucellosis caused by RB51.
RB51 is a weakened strain of Brucella used to vaccinate young female cattle against infection with more serious strains of Brucella. Vaccinating cows with the RB51 vaccine helps prevent abortions in cows and reduces the risk of people coming into contact with cows infected with more severe strains of Brucella. However, in rare cases, vaccinated cows can shed RB51 in their milk.
Testing of milk from the individual cows in the dairy herd revealed two cows that were infected with Brucella RB51, supporting the conclusion that these cows are a source of the RB51 contamination of the dairy’s raw milk. Testing is ongoing by Texas officials to assure that the remaining cows in the herd do not pose an ongoing risk of RB51 contamination of the dairy’s raw milk. The only way to avoid this potential exposure is to drink milk that has been pasteurized to kill the germs.
Raw milk and raw milk products are those that have not undergone a process called pasteurization that kills disease-causing germs. The CDC recommends that people only drink milk that has been pasteurized to kill germs. Even healthy animals may carry germs that can contaminate milk. There is no substitute for pasteurization to assure that milk is safe to drink.
The risk of getting sick from drinking raw milk is greater for infants and young children, the elderly, pregnant women, and people with weakened immune systems, such as people with cancer, an organ transplant, or HIV/AIDS. However, healthy people of any age can get very sick if they drink raw milk contaminated with harmful germs.
See the CDC Announcement
See also Medical Law Perspectives Report: Foodborne Illness: When Grabbing a Bite Can Be Deadly