Serum Ferritin as a Predictor of Disease Severity in Dengue: A Prospective Observational Study

Background: Dengue is a major mosquito-borne viral illness affecting children in tropical and subtropical countries. Although most infections are self-limiting, a proportion of patients progress to severe dengue with complications such as plasma leakage, shock, bleeding, and organ dysfunction. Early identification of children at risk of severe disease remains a clinical challenge. Serum ferritin, an acute-phase reactant and marker of immune activation, has emerged as a potential biomarker for predicting disease severity. The aim is to evaluate whether serum ferritin can be used as an early predictor of dengue severity in pediatric patients. The objective is to predict early complications and identify children requiring close monitoring using serum ferritin as a prognostic marker, and to determine the correlation between serum ferritin levels and dengue severity. Material and Methods: This prospective observational study was conducted over 18 months in the Department of Paediatrics, Bokaro General Hospital, Bokaro, Jharkhand. A total of 100 children aged 2 months to 12 years with NS1 antigen-positive dengue infection were enrolled. Clinical details, laboratory investigations, and serum ferritin levels measured by particle-enhanced immunoturbidometric assay on Day 3 and Day 4 of illness were recorded. Patients were classified into non-severe and severe dengue. Statistical analysis was performed using SPSS version 27.0. Continuous variables were compared using the independent Student's t-test, while categorical variables were analyzed using the Chi-square or Fisher's exact test. A p-value <0.05 was considered statistically significant. Results: Among the 100 patients, 79% had non-severe dengue and 21% had severe dengue. The mean age was 7.00 ± 3.18 years, with a slight male predominance (52%). Shock was observed in 15% of patients, bleeding in 3%, and organ involvement in 5%. The mean serum ferritin level on Day 3 was significantly higher in severe dengue than in non-severe dengue (842.33 ± 106.61 ng/mL vs. 385.35 ± 87.71 ng/mL; p<0.0001). Similarly, the mean Day 4 serum ferritin level was significantly higher in severe dengue (1307.24 ± 111.08 ng/mL) compared with non-severe dengue (554.76 ± 149.87 ng/mL; p<0.0001). Serum ferritin categories on both Day 3 and Day 4 showed a highly significant association with dengue severity (χ²=85.53 and 86.03, respectively; p<0.0001). Children with severe dengue also had a significantly longer duration of fever than those with non-severe disease (5.33 ± 0.73 vs. 4.70 ± 0.70 days; p=0.0004). Conclusion: Serum ferritin demonstrated a strong positive association with dengue severity and was significantly elevated in children who developed severe disease. Measurement of serum ferritin during the early phase of illness may serve as a simple, accessible, and reliable biomarker for early risk stratification, enabling prompt identification of high-risk patients and facilitating timely monitoring and appropriate clinical intervention.

Keywords: Dengue, Serum ferritin, Severe dengue, Children, Biomarker, Disease severity, Prognostic marker.