Brucella

Brucella is the cause of brucellosis, which is a zoonosis transmitted by ingesting contaminated food (such as unpasteurized milk products), direct contact with an infected animal, or inhalation of aerosols. Transmission from human to human, for example through sexual intercourse or from mother to child, is exceedingly rare, but possible. Minimum infectious exposure is between 10 and 100 organisms. Brucellosis can affect any organ or organ system, and 90% of patients have a cyclical (undulant) fever. Though variable, symptoms can also include these clinical signs: headache, weakness, arthralgia, depression, weight loss, fatigue, and liver dysfunction. Foul-smelling perspiration is considered a classical sign. Between 20 and 60% of cases have osteoarticular complications - arthritis, spondylitis, or osteomyelitis. Hepatomegaly may occur, as can gastrointestinal complications.