Divya Lakshmi, Ramya Ramanathan, Sundari Subramanian
Dengue is a re-emerging tropical disease transmitted by mosquitoes. This cross-sectional study was conducted in the Department of Paediatrics of a tertiary care centre in South India over two years. Children and adolescents aged 0-15 years who presented with fever and were confirmed to have dengue by serological tests were included in this study. Blood was collected and sent for complete blood count (CBC) on day 3 of illness. Neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) were derived. The sensitivity of NLR and PLR was 68.4% and 96.8% respectively, while the specificity of NLR and PLR were 41.7% and 66.7% respectively. Although PLR was found to have higher sensitivity and specificity, NLR was found to have an increased positive predictive value. The platelet-lymphocyte ratio demonstrates superiority by overall accuracy, specificity, and sensitivity, proving to be a more effective marker for identifying severe dengue cases. NLR and PLR demonstrated a strong positive correlation (r = 0.83, p <0.001). The clinical utility of these ratios has been extensively studied in other diseases, such as sepsis and COVID-19, especially in adults, but has been underutilized in children due to the lack of knowledge and limited research.