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


Brucellosis is an infection caused by a bacteria.


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 in the eye

Rarely, it can pass between people by:

  • Breastfeeding—if mother has infection
  • Sexual contact
  • A transplant from an infected donor

Risk Factors

Your risk may be higher if you:

  • Drink raw milk
  • Eat undercooked meat, specially organ meat
  • Work around animals such as dairy workers, sheep and goat herders, farmers, veterinarians, and animal processing workers


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

  • General feeling of illness
  • Get tired easily
  • Headache
  • Muscle or joint pain
  • Fever (may be lower in day, and increase at night)
  • Chills
  • Severe headache and backache
  • Nausea, vomiting, or diarrhea
  • Rash

Some symptoms may last longer or happen later such as:

  • Recurrent fevers
  • Weight loss
  • Swelling of organs such as heart, liver, or spleen

Women who have the infection early in their pregnancy may have a higher risk of miscarriage.


Your doctor will ask about your symptoms and health history. Questions about travel history may also be asked. A physical exam will be done. There are a number of issues that may cause your symptoms. Tests will help your 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 linger. Early care may help to lower the chance of long-term health problems.

Care include:

  • Antibiotics —to treat the infection. Treatment may need 2 or 3 different antibiotics at the same time.
  • Surgery —for complications that are not treated with antibiotics.


Steps to lower the chances of brucellosis include:

  • Avoid unpasteurized milk and dairy foods.
  • Wear rubber gloves and goggles when working with livestock, their bodily fluids, or carcasses. Cover open sores on your skin.
  • Keep up with livestock vaccines. Talk to a veterinarian or your local health department for help.

Centers for Disease Control and Prevention

US Department of Agriculture


Alberta Health

Public Health Agency of Canada


Brucellosis. Centers for Disease Control and Prevention website. Available at: Updated September 13, 2017. Accessed September 27, 2019.

Brucellosis. EBSCO DynaMed Plus website. Available at: Updated August 4, 2017. Accessed September 27, 2019.

Patel PJ, Kolawole TM, Sharma N, a-Faqih S. Sonographic findings in scrotal brucellosis. J Clin Ultrasound. 1988;16(7):483-486.

Last reviewed September 2019 by David L. Horn, MD, FACP