The Significance of Brucella Abortus Agglutinins in Human Serum

Abstract

Abstract The work of several investigators has shown that agglutinins specific for Brucella abortus may be demonstrated in human serum. In many cases, such antibodies are present in the serum from an individual who is showing no visible symptoms of undulant fever. Because of such findings, the diagnostic value of the agglutination test is questioned, particularly by those who have not made extensive examinations and who are not familiar with the procedure. The interpretation of the agglutination by human serum of an antigen prepared from cultures of Br. abortus demands careful scrutiny. We, therefore, considered it very important to obtain definite information regarding the following questions. Are the agglutinins specific for Br. abortus, Br. melitensis or some other closely related specie?Is the presence of abortus agglutinins in human serum caused by an infection with Br. abortus from which the individual has recovered?Do the agglutinins result from an ingestion of milk or other dairy product containing the living organisms and are they then harbored in the tissues, such as the lymph nodes, without causing symptoms of undulant fever?Is the presence of the agglutinins in the blood serum due to their absorption from the gastro-intestinal tract after the drinking of milk containing abortus antibodies?When agglutinins are present in the serum of a patient showing symptoms suggestive of the disease, is a diagnosis of undulant fever justifiable?What serum titer is indicative of undulant fever?Do the agglutinins result from an ingestion of milk or other dairy product containing the living organisms and are they then harbored in the tissues, such as the lymph nodes, without causing symptoms of undulant fever?Is the presence of the agglutinins in the blood serum due to their absorption from the gastro-intestinal tract after the drinking of milk containing abortus antibodies?When agglutinins are present in the serum of a patient showing symptoms suggestive of the disease, is a diagnosis of undulant fever justifiable?What serum titer is indicative of undulant fever?