The human version of the disease caused by bacteria of the genus Brucella, principally Brucella abortus which causes brucellosis in cattle. In man it may cause a variety of symptoms from mild headache to crippling joint pains, incapacity or general apathy. In particular it affects people whose occupations bring them in contact with infected animals. The disease can also be contracted through unpasteurized milk and milk products, and improperly cooked animal products. It is a serious public health problem.