Study of Correlation of Serum Calcium Level with Disease Severity in Dengue Patients.

Unlabelled: Dengue fever is the world's fastest growing vector borne viral disease. Dengue infection has high morbidity and mortality unless managed promptly and appropriately. Calcium regulates many physiological processes such as neuromuscular transmission, heart contractility, hormonal release, blood coagulation and is essential for cell function. Low calcium level is present in almost 80% of dengue cases and is more associated with severe cases. Hypocalcemia enhances the binding of the dengue virus to monocyte macrophages and cells of T cell and B cell lineages in dengue infection. However, there is scarcity of literature on calcium homeostasis in dengue infection, and current guidelines do not address the necessity to monitor or correct blood calcium levels in dengue patients. In present study, we evaluated serum calcium level in dengue patients and correlated it with disease severity.

Material: The present observational cross-sectional study conducted in the Department of Medicine and Biochemistry, VMMC and Safdarjung Hospital, New Delhi, included 60 patients of dengue infection, satisfying the inclusion and exclusion criteria over a period of 18 months. Inclusion criteria were patients with age above 12 years, any gender, and diagnosed as having dengue infection, either by NS1Ag or by IgM ELISA for dengue antibodies, were clinically classified as Dengue Fever (DF), Dengue Haemorrhagic Fever (DHF), and Dengue Shock Syndrome (DSS) as per National Guidelines for Clinical Management of Dengue Fever developed by NVBDCP. Exclusion criteria were patients with diseases like hypertension, diabetes, cardiac disease, liver disease, malabsorption syndrome, renal dysfunction and patients taking drugs causing hypocalcemia and oral calcium and vitamin D supplements. In present study, serum calcium level used was corrected for hypoalbuminemia.

Observation: The mean age was 27 years with a male and female ratio of approximately 3:2. The present study shows that the mean serum calcium level (mg/dL) of patients in Dengue Fever, Dengue Haemorrhagic Fever and Dengue Shock Syndrome was 8.85, 8.27 and 7.95 respectively(p<0.0001). Serum calcium level was lower in DSS and DHF patients than DF patients. Negative correlation between severity of dengue infection and serum calcium level was found with correlation coefficient of -0.892.

Conclusion: The present study revealed significant negative correlation between Serum calcium level and severity of dengue infection. Therefore, it can be considered to use serum calcium level as a potential biomarker in order to identify severe dengue patients and this investigation will help in early identification, diagnosis and management of dengue infection but further studies are required to support this.