Study of Serum Calcium Levels as Early Prognostic Indicator and Its Association with Severity and Outcome of Dengue Fever

Abstract

Background: Dengue fever is a significant vector-borne disease caused by the Dengue virus, transmitted by Aedes aegypti and Aedes albopictus mosquitoes. It presents with a wide clinical spectrum, from mild fever to severe manifestations like Dengue Haemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS). Early identification of severe cases is crucial for better management and reducing complications. Serum calcium plays a vital role in vascular integrity and coagulation, and its depletion has been associated with severe dengue cases.

Aim: To evaluate serum calcium levels as an early prognostic indicator in predicting the severity and outcome of dengue fever.

Materials and Methods: An observational cross-sectional study was conducted on 130 dengue-NS1Ag, IgM positive patients at Aarupadai Veedu Medical College. Patients aged 18–70 years were included. Serum calcium levels corrected for albumin were measured during different phases of dengue fever—febrile, critical, and convalescent. Categorised them as MILD/SEVERE DENGUE based on WHO CRITERIA of 1997. Statistical analysis was performed using SPSS version 28, with significance set at p < 0.05.

Results: The mean age of patients was 32.27 years, with a marginal female predominance (51.5%). Among the study population, 65.4% exhibited warning signs, including plasma leakage (54.2%) and abdominal pain with vomiting (45.8%). Blood transfusion was required in 47.7% of cases. Mild dengue was observed in 87.7%, while severe dengue occurred in 12.3% of patients. Serum calcium levels significantly decreased in the critical phase (8.51±0.61 mg/dL) compared to the febrile phase (8.62±0.57 mg/dL, p<0.05) and remained lower in the convalescent phase (8.52±0.63 mg/dL, p<0.05). Patients with severe dengue had significantly lower calcium levels than those with mild dengue (p<0.05).

Conclusion: The study establishes a strong correlation between declining serum calcium levels and dengue severity. Serum calcium monitoring may serve as an early prognostic marker, allowing timely intervention to prevent complications. Further research is required to explore the role of calcium supplementation in dengue management.