A card test for the serodiagnosis of human leptospirosis.

A macroscopic agglutination test for detecting leptospiral antibodies in human sera is described. The test utilizes a stained preparation of non-pathogenic leptospires and is performed on the Brewer diagnostic cards used for bovine brucellosis screening. The agglutination of the stained antigen is more easily observed than the current macroscopic slide test using unstained leptospiral antigens. The non-pathogenic serotype patoc is agglutinated by sera from humans infected with serotypes pomona, hardjo, ballum, and copenhageni with a sensitivity of 94% in comparison with the microscopic agglutination test.