Two methods for rapid serological diagnosis of acute leptospirosis

Clin Diagn Lab Immunol. 2001 Mar;8(2):349-51. doi: 10.1128/CDLI.8.2.349-351.2001.

Abstract

Leptospirosis is a common and underdiagnosed zoonosis. Two rapid assays for serological diagnosis of acute leptospirosis in diagnostic laboratories, the immunoglobulin M (IgM)-dipstick assay and the indirect hemagglutination assay (IHA), were evaluated and compared with standard assays. Sera were examined from 104 patients admitted to a hospital for investigation in a leptospirosis diagnostic protocol. Specimens for serology were taken on days 1 and 4 of the patients' hospital stay. Antibodies were detected using an IgM-enzyme-linked immunosorbent assay (ELISA), microscopic agglutination test (MAT), an IgM-dipstick assay, and an IHA. Fifty-one patients were found to have leptospirosis. The sensitivity of the IgM-dipstick assay was 98%, its specificity was 90.6%, its positive predictive value was 90.9%, and its negative predictive value was 98%. The sensitivity of the IHA was 92.2%, its specificity was 94.4%, its positive predictive value was 95.9%, and its negative predictive value was 92.7%. The standard IgM-ELISA and MAT, were positive in the first samples tested from 67 and 55% of the cases, respectively, and the rapid IgM-dipstick assay and IHA were positive in 71 and 49%, respectively, in the first sample tested. Both rapid assays are highly sensitive and specific. Neither requires specialized equipment, and both are suitable for use in diagnostic laboratories.

Publication types

  • Comparative Study

MeSH terms

  • Acute Disease
  • Enzyme-Linked Immunosorbent Assay
  • Hemagglutination Tests / standards*
  • Humans
  • Immunoglobulin M / analysis
  • Leptospirosis / diagnosis*
  • Leptospirosis / immunology
  • Predictive Value of Tests
  • Reagent Strips / standards*
  • Sensitivity and Specificity

Substances

  • Immunoglobulin M
  • Reagent Strips