Brucellosis is a bacterial infection.


The bacteria infects livestock such as sheep, goats, cattle, deer, elk, and pigs. Humans get the bacteria from infected livestock by:

  • Eating or drinking animal products
  • Inhaling the bacteria
  • Contact through cuts in your skin or fluids in your eye

Rarely, it can pass between people by:

  • Breastfeeding—from an infected mother to her baby
  • Sexual contact
  • A transplant from an infected donor

Risk Factors

Your risk may be higher if you:

  • Work with livestock, their waste products, bodily fluids, or carcasses
  • Eat or drink unpasteurized dairy products
  • Eat undercooked meat products
  • Live in or travel to places where the bacteria is common


In most cases, symptoms appear within 2-4 weeks after infection. However, symptoms can appear from 5 days to several months after.

Early symptoms may involve:

  • General feeling of illness—malaise
  • Fatigue
  • Headache
  • Muscle or joint pain
  • Fever
  • Chills
  • Severe headache and backache
  • Nausea, vomiting, or diarrhea
  • Rash

Brucellosis causes a high fever (104°F-105°F). It goes up in the evening and returns to normal by morning. Evening fevers can also cause severe sweating. This cycle lasts 1-5 weeks. In some people, the fever will return. It may do so once or many times over months or years.

In addition to the list above, late symptoms may involve:

  • Loss of appetite
  • Weight loss
  • Belly pain
  • Weakness
  • Irritability
  • Insomnia

Serious problems may involve:

  • Abscesses within the liver or spleen
  • Enlargement of the liver, spleen, or lymph nodes
  • Inflammation and infection of organs in the body, such as:
  • Scrotal swelling

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

Bacterial endocarditis, aortic valve

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Your doctor will ask about your symptoms, and healthl and travel history.

You may also have:

  • A physical exam
  • 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. Finding it early and starting care will lower the chance of long-term health problems.

Care include:

  • Antibiotics to treat the infection. You may need to take them for up to 6 weeks.
  • Surgery to treat abscesses or infections that don't go away after taking antibiotics.


To help lower your chances of brucellosis:

  • Avoiding unpasteurized milk and dairy foods. If you aren’t sure if food or drink is safe, avoid it.
  • Wearing rubber gloves and goggles when working with livestock, their bodily fluids, or carcasses. Cover open sores on your skin.
  • Wearing a protective mask when working with brucellosis cultures.
  • Keeping 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 May 14, 2018.

Brucellosis. EBSCO DynaMed Plus website. Available at: Updated August 4, 2017. Accessed May 14, 2018.

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

Last reviewed May 2018 by David L. Horn, MD, FACP  Last Updated: 5/14/2018