ASSOCIATION OF CRP (q), IL-6 AND PROCALCITONIN WITH SEVERITY OF SCRUB TYPHUS

Background: Scrub typhus, caused by Orientia tsutsugamushi, is an important cause of acute undifferentiated febrile illness in India and is frequently associated with severe complications and multi-organ dysfunction. Early prediction of disease severity remains challenging due to nonspecific clinical presentation. Inflammatory biomarkers such as quantitative C-reactive protein (CRP), interleukin-6 (IL-6), and procalcitonin may serve as useful predictors of severity and outcome.Objectives: To evaluate the association of CRP (q), IL-6, and procalcitonin levels with disease severity in patients diagnosed with scrub typhus.Materials and Methods: This prospective observational study was conducted in the Department of Microbiology, Bhima Bhoi Medical College and Hospital, Balangir, Odisha, over a one-year period from August 2024 to July 2025. A total of 120 laboratory-confirmed scrub typhus patients were enrolled. Serum CRP (q), IL-6, and procalcitonin levels were measured at admission. Patients were classified into mild and severe scrub typhus based on clinical and laboratory criteria. Biomarker levels were compared between the two groups using appropriate statistical tests.Results: Of the 120 patients, 38 (31.7%) developed severe scrub typhus. Mean levels of CRP (76.9 ± 24.3 mg/L), IL-6 (128.5 ± 46.9 pg/mL), and procalcitonin (3.18 ± 1.27 ng/mL) were significantly higher in patients with severe disease compared to those with mild illness (p <0.001). IL-6 showed the strongest association with disease severity, followed by procalcitonin and CRP.Conclusion: Elevated CRP (q), IL-6, and procalcitonin levels are significantly associated with severe scrub typhus. Among these, IL-6 appears to be the most sensitive marker for predicting severe disease. Early assessment of these biomarkers may aid in risk stratification and timely management, potentially reducing morbidity and mortality.