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Overview

What Is Brucellosis?

Brucellosis is a bacterial infection that can spread from infected animals to people. It is also called Malta fever and may cause brucellosis disease symptoms that last for weeks or months. People can become infected through contact with infected animals or by consuming contaminated animal products, especially unpasteurized milk and dairy foods. The infection can affect brucellosis in humans as well as many types of livestock and other animals.

Symptoms

Brucellosis Symptoms

Brucellosis symptoms may begin days to months after exposure. They can be mild and nonspecific at first, and some people develop symptoms that persist or return over time.

  • Fever
  • Sweating
  • Fatigue
  • Headache
  • Muscle pain (myalgia)
  • Joint pain (arthralgia)
  • Weight loss
  • Loss of appetite

How It Spreads

How Brucellosis Spreads

  • Drinking unpasteurized milk or eating unpasteurized dairy products can transmit Brucella bacteria.
  • Eating contaminated animal products can cause infection if they are not handled or cooked safely.
  • Inhaling contaminated particles can spread infection, particularly in barns, slaughterhouses, or laboratories.
  • Contact with infected animal tissues or fluids can transmit the bacteria through the eyes, mouth, or broken skin.

Cattle, goats, sheep, pigs, camels, and dogs can carry different Brucella species. For example, brucellosis in cattle and brucellosis in dogs are linked to different animal reservoirs, including Brucella abortus and Brucella canis. Direct person-to-person transmission is rare.

Exposure risk

Higher-risk work and animal contact

Veterinarians, livestock workers, slaughterhouse workers, hunters, laboratory workers, and people assisting with animal births or miscarriages may have greater exposure risk. Protective equipment and workplace biosafety procedures can help reduce contact with infectious fluids and tissues.

Risk Factors

Risk Factors for Brucellosis

  • Consuming unpasteurized milk, cheese, or other dairy products increases exposure risk.
  • Working with livestock or animal tissues can lead to contact with Brucella bacteria.
  • Laboratory work involving Brucella cultures or specimens can cause occupational exposure.
  • Hunting or working in a slaughterhouse may involve contact with infected animals or tissues.
  • Living in or traveling to an area where brucellosis is common increases the chance of exposure.
  • Having close contact with infected dogs can increase the risk of canine brucellosis transmission.

Some risk factors can often be reduced, such as choosing pasteurized foods and using protective equipment. Other factors, including unavoidable occupational duties and the prevalence of infection in local cattle, goats, sheep, or dogs, may be harder to change.

Complications

Brucellosis Complications

  • Arthritis or osteomyelitis can affect the joints or bones.
  • Endocarditis can involve the heart valves or inner lining of the heart.
  • Meningitis or encephalitis can affect the membranes around the brain or the brain itself.
  • Liver or spleen involvement can cause inflammation or enlargement of these organs.
  • Persistent fatigue can continue after the initial infection.
  • Reproductive complications can affect pregnancy or reproductive organs.

Diagnosis

How Brucellosis Is Diagnosed

Diagnosis can be difficult because brucellosis disease symptoms resemble those of other infections. Clinicians may ask about animal contact, unpasteurized foods, travel, occupation, possible laboratory exposure, and when symptoms began, along with performing a physical examination.

  • Blood cultures or other cultures may be used to try to grow and identify Brucella bacteria.
  • Brucella antibody testing can look for an immune response to the infection.
  • Molecular testing, when available, may detect Brucella genetic material.
  • Imaging or specialist evaluation may be needed when complications affecting bones, joints, the heart, or nervous system are suspected.

Tell your clinician

Mention possible Brucella exposure

Tell your clinician and the laboratory about possible Brucella exposure before specimens are collected. The organism can pose a laboratory safety risk, and testing may require special handling.

Treatment & Management

Brucellosis Treatment and Management

Brucellosis treatment usually involves two or more antibiotics prescribed for an extended course. The exact medicines and duration depend on age, pregnancy, the infection site, relapse risk, and the Brucella species involved. Treatment decisions should be made with a clinician rather than through self-treatment.

  • Complete the full antibiotic course even if symptoms improve before the medicine is finished.
  • Attend follow-up visits and testing recommended by the treating clinician.
  • Monitor for returning symptoms or other signs of relapse.
  • Treat focal complications involving the bones, joints, heart, nervous system, or other organs.
  • Infectious-disease specialists may help manage severe, recurrent, or complicated infection.

Treatment safety

Use a regimen made for your situation

Do not self-treat with leftover antibiotics. Pregnancy, childhood, allergies, and possible exposure to the RB51 strain require regimen-specific medical guidance.

Prevention

How to Prevent Brucellosis

  • Choose pasteurized milk, cheese, and other dairy products.
  • Cook meat thoroughly before eating it.
  • Wear gloves, eye protection, and protective clothing around animals and animal tissues.
  • Cover skin wounds before handling animals or animal products.
  • Wash your hands after contact with animals, animal tissues, or animal fluids.

Veterinary control programs, testing and management of infected herds, and responsible breeding practices help reduce brucellosis in cattle, goats, sheep, and dogs. These measures are important for controlling brucellosis in cattle, bovine brucellosis, and canine brucellosis in animal populations.

Outlook and Prognosis

Brucellosis Outlook and Prognosis

The outlook is generally good when brucellosis is diagnosed and treated promptly. Recovery may take weeks to months, and fatigue or other symptoms can linger after treatment. Persistent infection, relapse, and complications are possible, especially when treatment is delayed or incomplete.

  • Prompt diagnosis and treatment generally support a better recovery.
  • The affected organ system influences the expected outcome.
  • Completing combination antibiotics lowers the risk of persistent infection and relapse.
  • Immune status can affect recovery and the risk of complications.
  • Pregnancy may require specialized treatment and follow-up.
  • Focal complications can make recovery longer or more complex.

When Should You See a Doctor

When Should You See a Doctor?

  • Contact a clinician for persistent fever with sweats or fatigue.
  • Seek medical evaluation for unexplained joint or muscle pain after animal exposure.
  • Talk with a clinician if illness develops after consuming unpasteurized dairy products.
  • Report symptoms after laboratory work or other occupational exposure to animals or animal tissues.

Seek urgent care

Know the emergency warning signs

Seek emergency care for severe chest pain, trouble breathing, confusion, fainting, severe headache with neck stiffness, or rapidly worsening illness. Tell emergency staff about any possible Brucella exposure.

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