Brucellosis

Brucellosis (undulant fever) affects primarily the reticuloendothelial system, the joints and at times the reproductive organs, heart, vessels, lungs, meninges and kidneys. Three organisms, B. melitensis, B. abortus, and B. suis may produce the disease. The reservoir of infection is in goats, cattle and pigs. Infection occurs through contaminated milk or through meat handling. The organ­isms lodge in the lymph nodes and then in the blood stream. Diagnosis is confirmed by agglutination of Brucella organisms by the patient's serum. In the common nonfatal form there is a low-grade undulating fever. loss of weight, cough or gastro-intestinal symptoms with enlargement of the lymph nodes and spleen. These symptoms may persist intermittently for years. A maculo-papular skin eruption and arthritis may occur. The characteristic lesion is granulomatous with an infiltrate of epithelioid cells, macrophages and giant cells resem­bling the Reed-Sternberg cell of Hodgkin's disease. In rare fatal cases with septicemia there is necrosis of lymphoid tissues and widespread thrombophlebitis. Infected em­boli may produce mycotic aneurysms.