This document presents information on the characteristics of brucellosis.
Brucellosis is a zoonotic infection of domesticated and wild animals, caused by organisms of the genus Brucella. Humans become infected by ingestion of animal food products, direct contact with infected animals, or inhalation of infectious aerosols. Brucellosis in humans has a strong association with military medicine. The ease of transmission by aerosol suggests that Brucella organisms might be a candidate for use as a biological warfare agent. Animals may transmit Brucella organisms during septic abortion, at the time of slaughter, and in their milk. Brucellosis is rarely, if ever, transmitted from person to person. Humans usually acquire Brucella organisms by ingestion of contaminated foods or slaughter of animals. The organism is highly infectious by the airborne route; this is the presumed route of infection of the military threat. Laboratory workers commonly become infected when cultures are handled outside a biosafety cabinet. Individuals presumably infected by aerosol have symptoms indistinguishable from patients infected by other routes: fever, chills, and myalgia are most common, occurring in more than 90 percent of cases. The bacterium may cause disease in virtually any organ system; large joints and the axial skeleton are favored targets and arthritis appears in approximately one third of patients. Fatalities occur rarely, usually in association with central nervous system or endocardial infection. A thorough history that elicits details of appropriate exposure is the most important diagnostic tool. When disease is considered, diagnosis is usually made by serology. The tube agglutination test remains the standard method. Nearly all patients respond to a 6 week course of oral therapy with a combination of rifampin and doxycycline; fewer than ten percent of patients relapse. Six weeks of doxycycline with addition of streptomycin for the first 3 weeks is also effective therapy. No vaccine is available for humans. 53 notes