Seroprevalence and Clinical Profile of Leptospirosis and Scrub Typhus in Clinically Suspected Patients at a Tertiary Care Center: A Retrospective Study from Theni, Tamil Nadu

Abstract

Background: Leptospirosis and Scrub typhus are zoonotic illnesses that are found worldwide. Scrub typhus is a rickettsial infection caused by Orientia tsutsugamushi and spread through the biting of a mite’s chigger. Leptospirosis is an anthropozoonotic illness that can be found anywhere but is most common in tropical and subtropical areas. In this study, we report the seroprevalence of Scrub typhus and Leptospirosis with relation to demographic factors in clinically suspected patients attending a tertiary care hospital in Theni, Tamil Nadu. Methods: This is a retrospective study in which 9574 serum samples from clinically suspected cases were collected from January 2018 to December 2023 and tested for immunoglobulin M (IgM) antibodies for Scrub typhus using the enzyme-linked immunosorbent assay (ELISA) and rapid test. A blood sample was taken from each patient, and an IgM ELISA was performed to make the diagnosis. The ELISA cut-off was determined. Results: In this study, 9574 probable cases, 4306 were examined for Leptospira IgM ELISA and 5268 for Scrub typhus IgM ELISA. Out of 4306 suspected Leptospira cases, 167 (3.8%) were positive and 485 (9.2%) were positive in 5268 suspected Scrub typhus cases. The bulk of Leptospirosis and Scrub typhus cases were in the 21–40 years’ age range, followed by the 0–20 years’ age range. Males were found to have higher seroprevalence (57.1%) than females (42.9%). Conclusions: Scrub typhus and leptospirosis are developing infections, and prompt treatment can save many lives. It is strongly advised to take a programmatic approach to the prevention, control, and management of these developing diseases.

Keywords

• enzyme-linked immunosorbent assay
• leptospirosis
• scrub typhus
• seroprevalence
• zoonosis