Evaluation of recombinantleptospiral surface antigen (Lsa27) lipoprotein for serodiagnosis of human leptospirosis by latex agglutination test.

Abstract

PURPOSE\nLeptospirosis has wide clinical presentations often mimicking other illnesses, thus rapid and simple diagnostics will have facilitated the initial patient management and therapy compared to other inaccessible and tedious tests/assays.\n\n\nMETHOD\nIn this study, the sensitized latex beads coated with purified recombinant outer membrane (OM)-leptospiral surface antigen (Lsa27) lipoprotein of pathogenic Leptospira was evaluated as a diagnostic antigen in latex agglutination test (LAT) for the detection of anti-leptospiral antibodies in the humans sera. The prepared rLsa27 beads were evaluated with the confirmed microscopic agglutination test (MAT) reactive (at 1:50) Leptospira-specific positive (n=42) and non-reactive negative (n=80) sera from humans cases suspected of leptospirosis with the history of pyrexia of unknown origin.\n\n\nRESULT\nThe results revealed the relative sensitivity (DSn) of 90.48 % (confidence interval (CI) at 95 %: 77.4 - 97.3%) and specificity (DSp) of 91.35 % (CI at 95 %: 82.8 - 96.4%), with an accuracy of 90.98 % (CI at 95 %: 84.44 - 95.41%), and the kappa value of 0.8036 ±0.056 SE (CI at 95%: 0.69 - 0.91) with a substantial agreement against gold standard serological MAT.\n\n\nCONCLUSION\nThe findings suggest that the rLsa27 protein-based LAT can be useful as a simple rapid screening diagnostic test for the detection of anti-leptospiral antibodies in the sera of humans. This rapid test can be complemented by other confirmatory diagnostics for the early detection of Leptospira antibodies which may in turn help in the prompt treatment and mitigates the public health problem at primary health care level.