Role of biomarkers in predicting mortality in patients with flaviviral disease endemic to South India: a retrospective observational study

Background: Flaviviral infections such as dengue and Kyasanur Forest Disease (KFD) are endemic causes of acute febrile illness in South India, with some cases progressing to severe disease and death. Methods: We conducted a retrospective observational study at a tertiary care centre from June 2023 to June 2024, enrolling 107 adults diagnosed with dengue (NS1/IgM positive) or KFD (Polymerase chain reaction assay-confirmed). Clinical and biomarker data, including haematological, hepatic, renal, inflammatory, and endothelial parameters, were analysed to find differences between the two diseases and identify predictors of 28-day mortality. Results: Eleven patients (10.3%) died within 28 days. KFD patients were older and had higher adrenomedullin and transaminase levels. Dengue cases showed higher SOFA scores and more severe thrombocytopenia. Mortality was associated with elevated coagulation markers, serum creatinine, procalcitonin, and adrenomedullin. Aspartate aminotransferase was more frequently elevated in non-survivors. Conclusions: Combining conventional and novel biomarkers, such as adrenomedullin, may help early identification of high-risk patients, improving prognostication and management of endemic flaviviral infections.