Brucellosis

Definition

Brucellosis is a disease caused by contact with animals carrying the brucella bacteria.

Alternative Names

Causes

Brucella bacteria infect cattle, goats, camels, dogs, and pigs. Transmission of the disease to humans occurs by contact with infected meat, contact with the placenta of infected animals, or eating or drinking unpasteurized milk or cheese.

The illness may be chronic and persist for years. Brucellosis is rare in the United States (except in the western states) and in visitors or immigrants from countries where it is prevalent (Spain, Mexico, South America, the Middle East).

Approximately 100 - 200 cases occur in the U.S. each year. People working in jobs requiring frequent contact with animals or meat -- such as slaughterhouse workers, farmers, and veterinarians -- are at high risk.

Acute brucellosis may begin with mild flu-like symptoms or with fever, chills, sweating, muscle aches (myalgia), joint aches (arthralgia), and malaise. Classically, fever spikes occur every afternoon to levels around 104 degrees Fahrenheit. "Undulant" fever derives its name from this undulating or up-and-down fever.

Symptoms

• Fever
• Chills
• Excessive sweating
• Weakness
• Weight loss
• Fatigue
• Headache
• Abdominal pain
• Enlarged liver
• Back pain
• Loss of appetite
• Joint pain

Additional symptoms that may be associated with this disease:

• Muscle pain
• Swollen glands

Exams and Tests

• Blood culture
• Clean catch urine culture
• CSF culture
• Bone marrow culture
• Serology detecting brucellosis antigen

This disease may also alter the results of the following tests:

• Quantitative immunoglobulins (nephelometry)
• Serum immunoelectrophoresis
• Febrile/cold agglutinins

Treatment

A combination antibiotic therapy, such as doxycycline and rifampin or an aminoglycoside, is recommended to treat and prevent relapse of infection. Longer courses of therapy may be required for complications.

Doxycycline is usually not prescribed for children until after all the permanent teeth have come in because it can permanently discolor the teeth that are still forming.

Outlook (Prognosis)

Relapse may occur, and symptoms may persist for years. As with tuberculosis, reactivation can occur after a long period of time.

Possible Complications

• Bone and joint lesions
• Infective endocarditis
• Encephalitis
• Meningitis
• Chronic fatigue syndrome

When to Contact a Medical Professional

Call for an appointment with your health care provider if you develop symptoms of brucellosis.

Also, call if your symptoms worsen or do not improve with treatment, or if new symptoms develop.

Prevention

Drinking and eating only pasteurized cheeses and milk is the most important preventative measure. People who handle meat should wear protective glasses and clothing and protect skin breaks from infection. Detecting infected animals controls the infection at its source. Vaccination is available for cattle, but not humans.

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