Key Points

• A 32 Fulani herdsman has developed an chronic, undulating fever, malaise, arthralgia (joint pains), profound fatigue, and increasing depression over the past month. He has had no abdominal discomfort or gastrointestinal irregularity. He has been treated at least twice for malaria, and he was given a course of amoxicillin for unclear reasons. He has also taken several different herbal preparations. More recently, has noted increasing localized pain in his right knee associated with some swelling of that joint. An accurate record of his fever is not available, but based on his history of chills and sweats, it would likely conform to the theoretical fever curve shown below:

• Physical examination showed a temperature of 38.1 degrees. The liver edge was palpable about 2 cm below the right costal margin, and the spleen tip was just palpable on deep inspiration, suggesting an enlargement of this organ also. The right knee is warm to the touch and there is a small effusion of fluid in the joint space. Laboratory tests suggest a mild anemia and elevation of the alkaline phosphatase, suggesting either increased pressure in the biliary tract or liver parenchyma, or a disolution of bone (both liver and bone contain alkaline phosphatase).

• Blood cultures and a culture fluid aspirated from the right knee are negative at 3 days, but the laboratory is instructed to hold the cultures for 3 weeks. A brucella agglutinin test on his blood is positive, so the patient is treated with doxycycline and gentamicin. His fevers begin to resolve slowly and his knee improves. 15 days after admission, his blood cultures grow Brucella abortus.