Association of NS1 Antigen, IgM/IgG Antibodies with Haematological Indices and Inflammatory Markers in Suspected Dengue Cases: A Cross-sectional Study

Abstract

Introduction: Dengue Virus (DENV) has been re-emerging as a major public health challenge in tropical and subtropical regions, including India, with increasing incidence, changing epidemiology, and seasonal outbreaks. Early diagnosis supported by laboratory markers is essential for effective clinical management and disease control. Aim: To evaluate the association of serological markers with haematological, biochemical and inflammatory parameters in clinically suspected cases of dengue. Materials and Methods: This cross-sectional study was conducted from March 2025 to December 2025 at Adarsh Multispecialty Hospital, Gandhinagar, Gujarat, India. The study included 154 patients presenting with Acute Febrile Illness (AFI). DENV diagnosis was performed using an immunochromatographic kit for NS1 antigen and IgM and IgG antibodies from the serum sample. Haematological indices, Inflammation markers and liver function tests Serum Glutamic Pyruvic Transaminase (SGPT) and Serum Glutamic Oxaloacetic Transaminase (SGOT) were examined. Chi-square test was used for statistical analysis, and a p-value of <0.05 was considered statistically significant. Results: A total of 154 suspected Dengue Fever (DF) samples were collected, out of which 38 cases of dengue infection were confirmed. The highest positivity was seen in the age group of 21 to 30 years, 14 (36.8%), with males being more affected, making up 24 (63.2%) of the cases. The seasonal peaks happened during August and September, with 11/34 (32.4%) and 11/42 (26.2%) of cases, respectively. Testing for the NS1 antigen alone found 17/74 (23%) of infections, but combining NS1 and antibody testing raised the rate to about 20/73 (27.3%). Dengue patients showed significantly decreased platelet counts 35/38 (92.1%), White Blood Cell (WBC) counts 21/38 (55.26%), and also lymphocyte counts 20/38 (52.63%). Liver enzymes were also elevated (SGOT 161.58±372.44 U/L and SGPT 187.46±456.09 U/L). They also showed raised C-Reactive Protein (CRP) in 33/38 (86.8%) of cases and higher Erythrocyte Sedimentation Rate (ESR) in 23/38 (60.5%) of cases. Conclusion: Detection of the NS1 antigen with antibody testing gives more specific results. Significant increase in CRP levels and a drop in platelet levels in dengue-positive patients are early indicators of presumptive diagnosis. Integrated haematological, and inflammatory markers facilitate efficient risk stratification and enhance early dengue identification, enabling prompt clinical therapy during periods of peak transmission.