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Health Information Center


  • Cynthia M. Johnson, MA
Publication Type:



(Undulant Fever; Malta Fever; Mediterranean Fever; Gibraltar fever)


Brucellosis is an infection from a bacteria. It can range from mild to severe. Early treatment may help prevent lasting health problems.


The bacteria infects livestock, such as sheep, goats, cattle, deer, elk, and pigs. The infection can pass to humans through:

  • Contaminated food or drinks
  • Undercooked or unpasteurized animal products
  • Inhaling the bacteria
  • Contact through cuts in the skin
  • Fluids splashed into the eye

Rarely, it can pass between people by:

  • Breastfeeding—if the mother is infected
  • Sexual contact
  • A transplant from an infected donor

Risk Factors

The risk of infection is higher in those who

  • Drink raw milk
  • Eat undercooked meat, especially organ meat
  • Work around animals such as:
    • Dairy workers and animal processing workers
    • Sheep and goat herders
    • Farmers
    • Veterinarians


Symptoms often appear within 2 to 4 weeks after infection. Some may appear earlier or several months later. Early symptoms may include:

  • Being tired easily
  • Headache and backache
  • Muscle or joint pain
  • Fever, especially at night
  • Chills
  • Nausea and vomiting
  • Loose stools (poop)
  • Rash

Some symptoms may last longer or happen later, such as:

  • A fever that returns
  • Weight loss

Organs such as the heart, liver, or spleen may swell.

Infection in early pregnancy may raise the risk of miscarriage .


The doctor will ask about symptoms, past health, and any recent travel. A physical exam will be done. Many health problems can cause these symptoms. Tests will help the doctor find a cause. Tests may include:

  • Blood tests
  • Bone marrow tests
  • Lumbar puncture to test the fluid that surrounds the brain and spinal cord
  • Tissue tests
  • Imaging tests, such as an MRI scan


Brucellosis goes away on its own in most people. Some health problems can take a long time to go away. Early care may help lower the risk of lasting problems.

Antibiotics may be given to treat the infection. More than one may be needed at the same time.

Surgery may be done to treat health problems that cannot be helped by antibiotics.


To lower the risk of brucellosis:

  • Do not consume unpasteurized milk and dairy foods
  • Follow safety steps when working with animals




  • Brucellosis. Centers for Disease Control and Prevention website. Available at: https://www.cdc.gov/brucellosis.
  • Brucellosis. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/brucellosis.
  • Tuon FF, Gondolfo RB, et al. Human-to-human transmission of Brucella - a systematic review. Trop Med Int Health. 2017;22(5):539-546.


  • David L. Horn, MD, FACP
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.