Volume: 46 Issue: 3
Year: 2026, Page: 213-226, Doi: https://doi.org/10.51248/v46i3.180
Received: Aug. 6, 2026 Accepted: Sept. 9, 2026 Published: Sept. 27, 2026
Background: Acute Febrile Illness (AFI), marked by nonspecific symptoms such as fever, myalgia, and arthralgia, is difficult to diagnose due to overlapping causes like Dengue, Chikungunya, Scrub typhus, and Leptospirosis. Limited diagnostic capacity often leads to delayed or inappropriate treatment. Aim: This study retrospectively evaluated AFI cases referred to tertiary care centers in Chennai from 2021 to 2023 to determine etiological distribution, seasonal trends, and demographic patterns. Methods: A total of 7,530 serum samples were subjected to ELISA-based assays targeting Dengue (NS1/IgM), Chikungunya (IgM), Scrub typhus (IgM), and Leptospirosis (IgM). Data were analyzed using ANOVA with post hoc tests to identify significant differences across years and diseases. Results: Dengue was the predominant AFI cause in all three years (17.5% in 2021, 18.7% in 2022, and 15.9% in 2023) followed by Scrub typhus (2.8–3.9%) and Chikungunya (0.4–1.7%). Leptospirosis occurred in 0.15% (2021) and 0.29% (2022), but was absent in 2023. Notably, most cases remained undiagnosed: 77.9% in 2021, 76.6% in 2022, and 83.0% in 2023. Seasonal clustering was observed: Dengue peaked between September and December, while Scrub typhus and Leptospirosis displayed sporadic seasonal patterns. Conclusion: AFI in Chennai is mainly driven by Dengue, with additional contributions from Scrub typhus and Chikungunya. The lack of Leptospirosis cases in 2023 may reflect temporal variation or referral bias. The high proportion of undiagnosed cases underscores diagnostic gaps. Strengthened point-of-care testing and syndromic management are essential for improving early detection, targeted treatment, and preventive efforts.
Keywords: Acute Febrile Illness, Dengue, Chikungunya, Scrub Typhus, Leptospirosis, Chennai epidemiology.
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Vasanth Mohandass, Ravi Kiran, Divya Sankaramourthy, Roshan Raj, Lakshmi Priya Navaneethakrishnan, Yamini Gopi, Santhosh Rajakumar, Bhavyaa Lakshmi Sole, Anupama Cherayi padinakara, Kaveri Krishnasamy. A Cross-Sectional Three-Year Retrospective Survey on Acute Febrile Illness in Chennai.Biomedicine: 2026, 46(3): 213-226. https://doi.org/10.51248/v46i3.180