Brucellosis

Brucellosis is an acute febrile illness that is transmitted to humans from animals. It's also called undulant fever, Malta fever, Gibraltar fever, Cyprus fever, and Mediterranean fever.

Brucellosis occurs throughout the world, but such measures as pasteurization of dairy products and immunization of cattle have reduced the incidence of brucellosis in the United States.

Sources of infection occur through travel abroad, consuming imported cheese, and occupation-related exposure. Brucellosis most frequently occurs among farmers, stock handlers, butchers, and veterinarians.

The incubation period usually ranges from 5 to 35 days but sometimes lasts for months. The prognosis is good. With treatment, brucellosis seldom is fatal although complications can cause permanent disability.

Causes

Brucellosis is caused by the nonmotile, non-sporeforming, gram-negative coccobacillus Brucella, notably B suis (found in swine), B. melitensis (in goats), B.abortus (in cattle), and B. canis (in dogs).

The disease is transmitted through the consumption of unpasteurized dairy products or uncooked or undercooked, contaminated meat. It's also passed on through contact with infected animals or their secretions or excretions.

Signs and Symptoms

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

Additional symptoms that may be associated with this disease:

• Muscle pain
• Swollen glands

Diagnostic tests

Brucellosis is diagnosed in a laboratory by finding Brucella organisms in samples of blood or bone marrow. Also, blood tests can be done to detect antibodies against the bacteria. If this method is used, two blood samples should be collected 2 weeks apart.

Treatment

The most effective therapy is a combination of doxycycline and aminoglycoside, such as streptomycin, gentamicin, or netilmicin for 4 weeks, followed by a combination of doxycycline and rifampin for 4 to 8 weeks. In pregnancy, trimethoprim-sulfamethoxazole can be given in combination with rifampin for 8 to 12 weeks. Alternative treatments include chloramphenicol, with or without streptomycin, and co-trimoxazole.

Cardiac surgery may be necessary in some cases.

Prevention

There is no human vaccine for brucellosis, but humans can be protected by controlling the disease in livestock. After checking to make sure an animal is not already infected, and destroying those that are, all livestock should be immunized. Butchers and those who work in slaughterhouses should wear protective glasses and clothing, and protect broken skin from infection.

Some experts suggest that a person with the disease refrain from engaging in unprotected sex until free of the disease. The sexual partners of an infected person should also be closely monitored for signs of infection.