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Animal and Plant Health Inspection Service
U.S. Department of Agriculture
USDA FAQ's and resources about coronavirus (COVID-19).  LEARN MORE

What is Swine Brucellosis

Swine brucellosis is an infectious disease of swine caused by Brucella suis (B. suis) biovars 1 or 3. Swine exposed to B. suis develop a bacteremia (bacterial infection in the blood). Infection can then localize in various tissues. The disease typically causes chronic inflammatory lesions in the reproductive organs which can cause abortions, infertility and low milk production. It may also localize in joints, leading to lameness. It’s important to note that swine brucellosis is potentially a zoonotic disease (people can contract it). People in direct contact with potentially infected swine should take precautions as directed by public health experts. Commercial swine in all 50 states, Puerto Rico and the U.S. Virgin Islands are free from swine brucellosis. However, feral swine and domestic swine in close contact with them remain a reservoir in the U.S. 

Treatment in affected animals is not curative. Disease prevention is the best approach since there is no vaccine or treatment for swine brucellosis.

Following acute bacteremia, symptoms can vary depending on the area of localization. Common manifestations are abortion, temporary or permanent sterility, orchitis (swollen testicles), lameness, posterior paralysis, stillborn, mummified or weak piglets.

Swine brucellosis should be reported immediately upon diagnosis or suspicion of the disease.

Also, please note and advise the client that swine Brucellosis can infect humans and positive results should initiate contact with their health care providers.

Swine brucellosis is usually spread mainly by ingestion of infected tissues (i.e. aborted fetuses, and other tissues of infected animals) or fluids (i.e. urine, semen). Infected boars may transmit the disease during mating.

Indemnity Information: for questions in regards to brucellosis indemnity, contact:

Nicki Humphrey, DVM
Veterinary Medical Officer-Swine Staff-ASEP
USDA-APHIS-Veterinary Services​


John A. Korslund, DVM
Swine Commodity Health Specialist
USDA, APHIS, VS, Surveillance, Preparedness, and Response Services
301-851-3468 Office 
301-821-7406 Cell

Producers should be aware of the disease and watch their herds closely for contact with feral swine, and immediately report that contact to their veterinarian, or state or federal regulatory officials. Suspected cases of swine brucellosis should be reported immediately upon diagnosis or suspicion of the disease.

Federal: State-assigned Assistant Director VS District Offices Points of Contact.

StateState Animal Health Officials. Also, please be aware that swine Brucellosis can infect humans; positive results should initiate contacts with your health care providers.

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