Two Methods for Rapid Serological Diagnosis of Acute Leptospirosis

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.

Leptospirosis Diagnosis: Competancy of Various Laboratory Tests

“…The test is both complex and tedious for routine use. Many studies have demonstrated Pan Bio ELISA to be more sensitive than MAT for detection of cases early in acute illness [34]. IgM antibodies start appearing during the first week of illness though antibody levels are low or not detectable very early on in the illness.…”

Identification and evaluation of LPS antigen for serodiagnosis of uveitis associated with leptospirosis

“…Assays that focus primarily on detecting IgM binding to crude antigen (Adler et al, 1980; Abbreviations: HRP, horseradish peroxidase; MAT, microscopic agglutination test; NC, nitrocellulose. Gussenhoven et al, 1997;Winslow et al, 1997;Smits et al, 1999;Levett et al, 2001), though more sensitive for serodiagnosis, are subject to variations in specificity. However, the nature of IgM-binding antigen has not been identified in these studies.…”

Risk Factors for Clinical Leptospirosis from Western Jamaica

“…The main aim of this study is to identify the risk factors associated with contracting leptospirosis in four western parishes of Jamaica. 16,17 A symptomatic patient with positive results by either of these methods is considered to have clinical leptospirosis by the Jamaica MOH. Controls were matched (1:n) to cases on neighborhood and age (±10 years).…”