Changing Trends in the Seroprevalence of Leptospirosis in Kelambakkam: A Ten-Year Retrospective Study

Introduction: Leptospirosis is a zoonotic infection affecting humans. The main sources of infection are animal reservoir hosts and man is the accidental host in the disease transmission process. The diagnosis is usually made by microscopy, culture, molecular techniques, and serological tests like ELISA, MAT (Microscopic Agglutination Test) and MSAT (Macroscopic Slide Agglutination Test). The ELISA method to detect IgM antibodies is used as a good cost-effective testing method. An increasing titre of IgM antibody is a sign of active leptospirosis. Aims and Objectives: The study aimed to evaluate the seroprevalence of Leptospirainfection over a 10-year period in a tertiary care hospital located in Kelambakkam village in Chengalpattu district. Material and Method: The samples were tested for the presence of specific Leptospira IgM antibodies in the patient’s serum using the Panbio Leptospira IgM ELISA kit. The samples were reported as positive/ negative/ equivocal accordingly. Results: This retrospective study included a total of 2035 patients, clinically suspected of leptospirosis, over a 10-year period from 2011 to 2021. 186 patients tested positive for specific IgM antibodies by ELISA method,giving an overall prevalence rate of 9.14%. Conclusion: The seroprevalence of leptospirosis over a time period of more than 10 years is highlighted in our study. Clinical suspicion of leptospirosis should be kept in mind at all times, especially now during the COVID-19 pandemic. The Panbio Leptospira IgM ELISA test kit used in our study proves to be a very useful method for diagnostic purposes, especially in limited-resource settings.