Brucellosis is a bacterial infection that spreads from animals to people — most often via unpasteurized milk, cheese and other dairy products. More rarely, the bacteria that cause brucellosis can spread through the air or through direct contact with infected animals.

Brucellosis symptoms may include fever, joint pain and fatigue. The infection can usually be treated successfully with antibiotics. Treatment takes several weeks to months, however, and relapses are common.

While brucellosis is uncommon in the United States, the disease affects hundreds of thousands of people and animals worldwide. Avoiding unpasteurized dairy products and taking precautions when working with animals or in a laboratory can help prevent brucellosis.

Symptoms Causes Risk factors Complications Prevention

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

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

Brucellosis symptoms may disappear for weeks or months and then return. In some people, brucellosis becomes chronic, with symptoms persisting for years, even after treatment. Long-term signs and symptoms include fatigue, fevers, arthritis and spondylitis — an inflammatory arthritis that affects the spine and adjacent joints.

When to see a doctor

Brucellosis can be hard to identify, especially in the early stages, when it often resembles many 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.

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