Assessment of the efficacy of an IgM-elisa and microscopic agglutination test (MAT) in the diagnosis of acute leptospirosis

ABSTRACT

In a prospective study in Barbados between 1979 and 1989, 321 cases were diagnosed in 638 patients presenting at a hospital with symptoms of leptospirosis. Initial diagnosis was based on patient history and characteristic signs and symptoms. In 92 cases (29 percent), diagnosis was confirmed by isolation of organisms from the blood, urine, or dialysate fluid; in the remaining 229 cases (71 percent) diagnosis was confirmed by serology alone. Results of an IgM-ELISA and microscopic agglutination test (MAT) in cases with isolates and in non-specificity of the tests. The sensitivity of IgM detection by ELISA was 52 percent in the first acute-phase specimen, increasing to 89 percent and 93 percent in the second acute-phase specimen, increasing specimens respectively. The specificity of the IgM-ELISA was high (> or =94 percent) in all specimens. The sensitivity of the MAT was low (30 percent) in the first acute-phase specimen, increasing to 63 percent in the second acute-phase specimen and 76 percent in the convalescent specimen. The specificity of the MAT was > or = 97 percent in all specimens. (AU)