Exposures to Drug-Resistant Brucellosis Linked to Raw Milk

Posted February 8, 2019

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Overview­

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The Centers for Disease Control and Prevention and state health officials are investigating potential exposures to Brucella strain RB51 (RB51) in 19 states, connected to consuming raw (unpasteurized) milk from Miller’s Biodiversity Farm in Quarryville, Pennsylvania. One case of RB51 infection (brucellosis) has been confirmed in New York, and an unknown number of people may have been exposed to RB51 from drinking the milk from this farm. This type of Brucella is resistant to first-line drugs and can be difficult to diagnose because of limited testing options and the fact that early brucellosis symptoms are similar to those of more common illnesses like flu.­

The New York case is the third known instance of an infection with RB51 associated with consuming raw milk or raw milk products produced in the United States. The other two human cases occurred in October 2017 in New Jersey and in August 2017 in Texas. Those cases reported drinking raw milk from an online retailer and a Texas farm, respectively. In addition to these three confirmed cases, hundreds of others were potentially exposed to RB51 during these three incidents.

Symptoms of Brucella Infection (Brucellosis)

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  • Initial symptoms of brucellosis can include fever, sweats, loss of appetite, headache, fatigue, muscle and joint pain, and potentially more serious complications.
  • In pregnant patients, Brucella infections can lead to miscarriage.
  • Symptoms can start anywhere from five days to six months after exposure.
  • People who are infected but are not treated can go on to develop more serious complications like arthritis; heart problems; enlargement of the spleen or liver; and, in rare cases, nervous system problems, like meningitis.

Advice to Consumers

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  • Raw milk and raw milk products are those that have not undergone a process called pasteurization that kills disease-causing germs.
  • 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. On rare occasions, cows vaccinated with RB51 vaccine can shed the bacteria in their milk. People who drink raw milk from cows that are shedding RB51 can develop brucellosis.
  • RB51 is resistant to rifampin, one of the antibiotics that would typically be used to prevent or treat brucellosis. CDC recommends that anyone who may have been exposed to RB51 go to their doctor to see if they need antibiotics to prevent infection and symptoms from developing.
  • People who consumed raw milk or raw milk products from this dairy farm since January 2016 may have been exposed and should talk to their doctor.
    • People who are still within six months of the date they last consumed the raw milk are at an increased risk for brucellosis and should receive antibiotics to prevent an infection and symptoms, and should monitor their health for possible symptoms for six months. If symptoms develop, they should see their doctor immediately for testing.
    • People who last drank raw milk from this dairy more than six months ago and have had symptoms of brucellosis – but not been treated – should see their doctor immediately for testing that can determine if they are infected and need antibiotics to prevent long-term health problems caused by brucellosis.
  • Discard any leftover or stored raw milk or raw milk products from this dairy farm.
Investigation Details
  • A New York resident, who drank raw milk purchased from Miller’s Biodiversity Farm in Quarryville, Pennsylvania, was diagnosed with brucellosis in November 2018.
  • Milk samples from Miller’s Biodiversity tested positive for  RB51. A cow that tested positive for RB51 has been removed from the milking herd.
  • 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.