Brucellosis is a systemic bacterial disease with acute or insidious onset, characterized by fever, sweats, weakness, malaise and weight loss. It may last for several days, months, or occasionally a year or more. The agents of infection in humans are Brucella abortus from cows, B. melitensis from goats, B. suis from pigs and B. canis from dogs.
Serological procedures have been the diagnostic method of choice because isolation of the organism is difficult. Wright’s procedure is a quantitative serological test that detects the acute form of brucellosis. When it is performed between the 10th and 15th day after onset of infection, the test detects primarily IgM antibodies to Brucella organisms. However, antibody titers rapidly fall below the limit of quantitation in this test. The qualitative Rose Bengal antigen test is used for detection of IgG antibodies. Because of the sensitivity of this test, it is valuable for screening and epidemiological studies.