Evaluation of two methods for rapid serological diagnosis of acute leptospirosis

ABSTRACT

OBJECTIVE: To evaluate two rapid assays for serological diagnosis of acute leptospirosis in diagnostic laboratories. DESIGN AND METHODS: 209 specimens were examined from 104 patients admitted to hospital for investigation in a leptospirosis diagnostic protocol. Specimens for serology were taken on days 1 and 4 of the hospital admission. Antibodies were detected using IgM-ELISA, microscopic agglutination (MAT), an IgM-dipstick assay and indirect haemagglutination assay. RESULTS: 51 patients were found to have leptospirosis. The sensitivity of the IgM-dipstick was 98 percent, specificity was 90.6 percent, positive predictive value was 90.9 percent and the negative predictive value was 98 percent. The sensitivity of IHA was 92. percent, specificity was 94.4 percent, positive predictive value was 95.9 percent and negative predictive value was 92.7 percent. The IgM-dipstick assay was positive in 71 percent of the cases in the first sample tested. CONCLUSIONS: Both assays are highly sensitive and specific. Neither requires specialized equipment, and both are suitable for use in diagnostic laboratories.(Au)