Evaluation of a Commercial Enzyme-Linked Immunosorbent Assay Kit for Detection of IgM Antibody against Leptospira in Human Sera for Patients admitted in Malaysian Hospitals

Leptospirosis is an infectious zoonotic disease caused by corkscrew shaped of pathogenic Leptospira spp. Early diagnosis is important as the disease can be treated with antibiotic to prevent complications. The gold standard of leptospirosis diagnosis is microscopic agglutination test (MAT). However, the test is laborious and time consuming. This study aimed to evaluate whether a commercial ELISA (enzyme-linked immunosorbent assay) kit by Virion- Serion can demonstrate antibody against leptospires for accurate and rapid screening for leptospirosis. A total of 212 serum samples were tested with Virion-Serion Classic ELISA IgM, which was earlier collected from patient with clinical manifestation suggestive of leptospirosis in Malaysia and confirmed with MAT. The results were analyzed into two categories. In the first category all samples that were positive with MAT but detected as intermediate by the ELISA were not included. In the second category, all sample that positive with MAT but detected as intermediate were included. When the intermediate results were excluded, the clinical sensitivity was 73% and clinical specificity was 94%. When the intermediate results were included, the clinical sensitivity and specificity were 75% and 85% respectively. From this finding we can conclude that Virion-Serion ELISA IgM Classic kit have a reasonably appropriate performance and can be used for screening and diagnosis for leptospirosis in acute febrile illness however it should be confirmed later with the gold standard serological test which is MAT.