Brucellosis is a bacterial infection caused by Brucella bacteria. There are several species of Brucella. Each species is commonly associated with a specific animal host; for example, Brucella abortus with cattle, Brucella melitensis with sheep and goats, Brucella canis with dogs, and Brucella suis with pigs. Currently, consuming unpasteurized dairy products causes most cases of brucellosis. There are occasional infections among laboratory workers handling Brucella cultures. Brucellosis occurs most often in people who have contact with livestock and in people who consume unpasteurized dairy products. The length of time between exposure and appearance of symptoms of brucellosis is usually one to three weeks, but can be as long as several months. The symptoms of brucellosis are nonspecific. They include fever, sweats, malaise, headache, and back pain. A recurring fever and arthritis is observed if patients go untreated for long periods. Infections that last for more than 12 months can result in infections in bones, joints, liver, kidney, spleen, or heart valves. It is necessary to treat patients with an appropriate antibiotic for prolonged periods. If therapy is discontinued too early, relapse of symptoms may occur. Best results are obtained when a combination of two or more antibiotics are used.
How can infection with brucellosis be prevented?
Elimination of the disease in domestic animals is the best prevention for brucellosis. Brucellosis control programs are based on vaccination and/or test-and-slaughter of infected animals. These programs have greatly reduced the incidence of animal disease in developed countries, and have resulted in a reduction in the number of human cases. Avoiding consumption of unpasteurized milk and dairy products and limiting exposure to infected domestic animals will prevent most human infections.