Brucellosis is a bacterial infection that spreads from animals to people. Most commonly, people are infected by eating raw or unpasteurized dairy products. Sometimes, the bacteria that cause brucellosis can spread through the air or through direct contact with infected animals.

Signs and symptoms of brucellosis may include fever, joint pain and fatigue. The infection can usually be treated with antibiotics. However, treatment takes several weeks to months, and the infection can recur.

Brucellosis affects hundreds of thousands of people and animals worldwide. Avoiding raw dairy products and taking precautions when working with animals or in a laboratory can help prevent brucellosis.

Brucellosis symptoms

Symptoms of brucellosis may show up anytime from a few days to a few months after you’ve been infected. Signs and symptoms are similar to those of the flu and include:

  • Fever
  • Chills
  • Loss of appetite
  • Sweats
  • Weakness
  • Fatigue
  • Joint, muscle and back pain
  • Headache

Brucellosis symptoms may disappear for weeks or months and then return. Some people have chronic brucellosis and experience symptoms for years, even after treatment. Long-term signs and symptoms may include fatigue, recurrent fevers, arthritis, inflammation of the heart (endocarditis) and spondylitis — an inflammatory arthritis that affects the spine and nearby joints.

When to see a doctor

Brucellosis can be hard to identify, especially in the early stages, when it often resembles other conditions, such as the flu. See your doctor if you develop a rapidly rising fever, muscle aches or unusual weakness and have any risk factors for the disease, or if you have a persistent fever.