Comparative Evaluation of Serological and  Molecular Techniques for the Diagnosis of  Leptospirosis in a Tertiary Care Centre

Visuvasam  Joshua; Dhanapaul  S; Priyadarshini  Shanmugam; Mohankumar  Appadurai

Visuvasam Joshua Assistant Professor, Department of Microbiology, Karpaga Vinayaga Institute of Medical Sciences and Research Centre, P O, GST Road, Chinnakolambakkam, Palayanoor, Maduranthakam, Tamil Nadu, India
Dhanapaul S Professor and Head, Department of Microbiology, Karpaga Vinayaga Institute of Medical Sciences and Research Centre, P O, GST Road, Chinnakolambakkam, Palayanoor, Maduranthakam, Tamil Nadu, India
Priyadarshini Shanmugam Professor and Head, Department of Microbiology, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Tamil Nadu, India
Mohankumar Appadurai Research Scholar, Department of Microbiology, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Tamil Nadu, India

Keywords: Leptospirosis, Immunochromatographic Test, Microscopic Agglutination Test, Igm Elisa, Weil’s Disease, Bacterial Zoonosis

Abstract

Introduction: Leptospirosis is a common bacterial infection, passed from animals to humans around the world. It presents with a wide range of symptoms. These can mimic other infections like dengue or typhoid, malaria and influenza. Hence, lab testing is required for diagnostic confirmation and initiation of early treatment which can be lifesaving, in some instances. Often, serological methods like IgM ELISA, rapid Immunochromatography, or molecular methods like PCR are used for laboratory diagnosis. The gold standard test, Microscopic Agglutination Test (MAT), is available only in reference laboratories.
Aim: To compare the diagnostic accuracy and utility of common serological tests in practice for diagnosing leptospirosis, such as Rapid IgM (Immunochromatography), IgM ELISA, real-time PCR, and Microscopic
Agglutination Test (MAT).
Methodology: Blood samples were collected from 208 patients presenting with fever, accompanied by headache, myalgia, or conjunctival suffusion, between December 2022 and June 2024 at a medical college hospital. All samples were tested by Rapid Leptospira IgM, Anti-Leptospira IgM ELISA, serovar-specific MAT, and Leptospira Real-time PCR. The diagnostic accuracy of each method was studied by comparing it with MAT, the
gold standard reference test.
Results: Among the 208 samples, 46 (22%) were IgM ELISA positive, 30 (14.4%) were MAT positive, 19 (9.33%) were real-time PCR positive, and 5 (2.4%) were positive by rapid IgM. The most prevalent serovar was Leptospira grippotyphosa with 50 % positivity. 208 samples tested, when compared against the reference gold standard MAT, IgM ELISA showed a sensitivity of 100% with a specificity of 92% whereas rapid IgM Immunochromatography demonstrated a low sensitivity of 17% with a higher specificity of 100%.
Conclusion: The Leptospira IgM ELISA method can be an effective screening tool for diagnosing leptospirosis, and samples positive by IgM ELISA should be confirmed with MAT or real-time PCR.

Keywords: Leptospirosis, Immunochromatographic Test, Microscopic Agglutination Test, Igm Elisa, Weil’s Disease, Bacterial Zoonosis

DOI: https://doi.org/10.24321/0019.5138.202624

How to cite this article:
Joshua V, Dhanapaul S, Shanmugam P, Appadurai M. Comparative Evaluation of Serological and
Molecular Techniques for the Diagnosis of Leptospirosis in a Tertiary Care Centre. J Commun Dis. 2026;58(2):9-16

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