The US Centers for Disease Control and Prevention (CDC) has announced an investigation of exposure to Brucella strain RB51 following consumption of unpasteurized milk from Miller’s Biodiversity Farm in Quarryville, Pennsylvania.
Health officials in 19 states are advised to be aware that individuals who present to their health care provider with fever, sweats, loss of appetite, headache, fatigue, muscle and joint pain, and report having consumed unpasteurized milk may have been exposed to RB51.
RB51 is resistant to rifampin, a first-line antibiotic that would be used to prevent or treat brucellosis. The CDC recommends that anyone who may have been exposed to RB51 go to visit their health care provider to be evaluated in order to prevent infection and symptoms from developing.
In November 2018, 1 case of brucellosis was confirmed in the state of New York. The case was confirmed in a resident who drank raw milk from the farm. Milk samples from the farm have also tested positive for RB51, but investigators indicate that the cow who produced the positive samples has been removed from the herd.
Although only 1 case has been confirmed, it is unknown how many individuals have been exposed to RB51 from raw milk consumption.
The New York case is the third known instance of an infection with RB51 associated with raw milk products in the United States. The other 2 human cases occurred in October 2017 in New Jersey and in August 2017 in Texas. In addition to these 3 confirmed cases, hundreds of others were potentially exposed to RB51 during these 3 incidents.
According to the CDC, “RB51 is a live, weakened strain used in a vaccine to protect cows against a more severe form of Brucella infection that can cause abortions in cows and severe illness in people.”
Following vaccination, it is rare, but possible, that cows can shed the bacteria in their milk and those who consume raw milk from cows that are shedding RB51 can develop brucellosis.
Brucellosis symptoms can present anywhere between 5 days to 6 months following exposure. The infection can be difficult to diagnose due to the similarity of symptoms to influenza and limited testing options. In addition to flu-like symptoms, infection with Brucella can lead to more serious complications including arthritis, cardiovascular problems, enlargement of the spleen or liver, and nervous system problems. Additionally, in pregnant women infections can lead to miscarriage.
The CDC has stated that individuals who consumed raw milk products from this dairy farm since January 2016 may have been exposed and should talk to their doctor.
The agency advises that individuals who consumed products from the farm within the last 6 months should receive antibiotics to prevent a Brucella infection. If symptoms develop, they should see their doctor immediately for testing.
For individuals who last consumed products from the farm more than 6 months ago, if any symptoms of brucellosis have been exhibited but not treated, testing should be performed immediately to determine infection status and whether antibiotics are needed.
At this time, any and all raw milk or raw milk products from this dairy farm should be thrown away.
As of January 22, 2019, investigators have determined that people in 19 states have bought or consumed raw milk from the implicated farm. The states are Alabama, California, Connecticut, Florida, Georgia, Iowa, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, and Virginia.
Contagion® will provide more information on this investigation as it becomes available.