The Isolation of Brucella Organisms from Apparently Healthy Individuals *

Although the etiological agent of brucellosis has been known for many years, this widespread infection remains one of the greatest enigmas in modern medicine. Perhaps the principal source of confusion is the difficulty of establishing a definite diagnosis of brucellosis. This is particularly true of the chronic form of this disease. While the history, clinical picture, laboratory procedures, intradermal tests, and pathological findings are of great assistance, a positive diagnosis usually can be made only by demonstrating the brucella organisms. These bacteria are quite difficult to culture, being very fastidious in their growth requirements and demanding a prolonged period of culture. If the tissue or blood being cultured is contaminated, or if aseptic technique is not carefully maintained in the collection of the material, the more slowly growing brucella may be overgrown by other organisms. It is essential that the proper carbon dioxide tension be maintained as the brucella organisms may be of the abortus species. Even in acute cases having chills, the number of brucella in the blood at a given time may be quite limited. Positive identification of the organisms requires specific antigen-antibody reaction. Even if brucella organisms are cultured from the tissues of a patient, does this prove that the patient has active brucellosis? Perhaps he may only be harboring the organisms in his body-in other words, he may be a brucella carrier. The distinction between a carrier and a person with active disease may be quite difficult to make; indeed, in chronic brucella infections this might be extremely difficult if not impossible. In recent years brucella have been implicated in such conditions as Hodgkin's disease,? duodenalulcer,5 psychoneurosis,8 neurasthenia,'4 multiple sclerosis,2 allergy,8 subacute bacterial endocarditis-,7 cirrhosis of the liver,' and hepatitis. Finding