Evaluation of a passive microcapsule agglutination test for the screening of human leptospirosis

Microcapsules, absorbed with two mixed antigens- each composed of 3 sonicated leptospira serovars — were developed in the past as a microcapsule agglutination test (MCA-LS) for the screening of clinical leptospirosis.Fof this study, fifty serum samples, taken at an earlier and at a later stage of illness from 25 Italian in-patients with clinical symptoms of leptospirosis, were tested with both the MCA-LS one-dilution test and the microscopic agglutination (MA) test, the confirmatory test for leptospirosis, with 18 leptospira strains circulating in Italy. Compared with MA, MCA-LS showed a sensitivity of 91.7%, and a specificity of 92.3%, including leptospiroses not substained by the diagnostic strains used in the MCA-LS kit.