Brucellosis is primarily a disease of farm animals caused by bacteria of the genus Brucella . There are many species of Brucella that infect horses, sheep, goats, pigs, cattle and dogs All can potentially infect people and cause flu-like illness and localized infections. The brucellosis eradication program in the United States has reduced the prevalence of this disease among animals, dramatically reducing the risk among people. There was one reported case of Brucellosis in New York City in 2001.
Everyone is susceptible to brucellosis, and may get the disease if exposed. Human infection rarely occurs. Those at greatest risk include veterinarians and farmers.
People can become infected through direct contact with tissues (especially placenta), blood, urine, and birth fluids from infected animals. Exposure can also occur through ingestion of contaminated food products. The most common source of human infection in the United States is unpasteurized dairy products. It is generally not transmitted from person to person.
Symptoms of brucellosis include intermittent or irregular fever of variable duration, headache, weakness, profuse sweating, chills, weight loss, and joint pains. Localized infections in the liver, spleen, bones or joints can occur. Chronic illness with undulating and recurring signs can occur for weeks or months if not treated. Fatality is rare, and usually only associated with heart complications from a species ( Brucella melitensis ) that does not occur in the United States.
The time period is highly variable, but symptoms usually appear within 5 to 30 days.
The diagnosis is made by isolation of the bacteria from blood, bone marrow, or other tissues, or by an antibody test.
Treatment for brucellosis can be difficult, and requires close oversight by a physician. Usually doctors will prescribe combination therapy using doxycycline and rifampin for 6 weeks to prevent recurring infection.
To reduce the risk of infection avoid eating unpasteurized dairy products, especially in countries where brucellosis may be more common or if you are not sure whether brucellosis is common. Also avoid contact with pregnant animals at the time of birth, and be sure to use proper hygiene following contact with animals.
Last Updated: October 2002