An infectious disease due to the bacteria Brucella that causes rising and falling (undulant) fevers, sweats, malaise, weakness, anorexia, headache, myalgia (muscle pain) and back pain.
Brucellosis is named after its bacterial cause. It also called undulant fever because the fever is typically undulant, rising and falling like a wave.
Brucellosis is transmitted through contaminated and untreated milk and milk products and by direct contact with infected animals (cattle, sheep, goats, pigs, camels, buffaloes, wild ruminants and, very recently, seals), and animal carcasses. Transmission can be through abrasions of the skin from handling infected animals. In the US, infection occurs more frequently by ingesting contaminated milk and dairy products. Groups at elevated risk include abattoir (slaughterhouse) workers, meat inspectors, animal handlers, veterinarians, and laboratory workers.
The incubation period of brucellosis is usually one to three weeks, but sometimes may be several months after exposure.
The symptoms are like those with many other febrile diseases, but with a marked effect on the musculoskeletal system evidenced by generalized aches and pains and associated with fatigue, prostration and mental depression. Urogenital symptoms may dominate the clinical presentation in some patients. The duration of the disease can vary from a few weeks to many months.