The appearance of Brucella agglutinins in significant titers following the administration of cholera vaccine has been reported to occur in 7 of 8 persons.1 In further observations2 on an additional 20 subjects given the standard two dose cholera vaccination, 80 per cent showed positive Brucella agglutination reactions in dilutions of 1/40 or higher, and 60 per cent showed positive reactions in dilutions of 1/160 or higher. One person showed agglutinins in dilutions as high as 1/2.560 partial and 1/1.280 complete. The reaction to the opsonocytophagic test also became positive after vaccination in 80 per cent of the 20 subjects. In 65 per cent of them, the test became strongly positive with phagocytosis by 80 to 100 per cent of the cells. The brucellergin cutaneous tes did not elicit a positive reaction after vaccination.
Studies on the antigenic interrelationship of Vibrio comma and the Brucella group indicate that a common antigen exists, identified as an H antigen of Vibrio comma.3
We have previously directed attention to the diagnostic confusion which may arise from the production of Brucella antibodies in response to cholera vaccination.4 The agglutination test is the most commonly used procedure for the diagnosis of brucellosis. A positive reaction even in low titers frequently,