Summary

• Human brucellosis is one of the world's most common zoonoses, with an incidence in certain countries exceeding 10 per 100,000 population, particularly in poor rural settings.
• Rarely fatal but relapse can occur with debilitating and economically devastating effects. It is considered a class B bioterrorist agent, is easily spread by aerosol, and is a significant hazard in microbiology laboratories.
• The 4 main human pathogens causing disease are Brucella melitensis, B abortus, B suis, and B canis.
• Most cases of brucellosis in Northern Europe and North America are acquired overseas and/or from consuming unpasteurised milk products, including cheese.
• The disease can affect any organ system and therefore presents in a variety of ways, especially as a prolonged fever of unknown origin, with associated rheumatic features in about 50% of cases. Diagnosis is based on clinical presentation and laboratory tests.
• Combination antibiotic therapy is the mainstay of treatment and should be used for prolonged periods to prevent relapse of symptoms. There is disagreement about the optimum treatment regimen.