Dengue NS1 Kinetics and its Utility as a Predictor of Severe Dengue Disease: An Ambispective Study

Background: Dengue is a febrile illness with varied clinical manifestations. The disease manifestations can vary from an asymptomatic infection to a severe infection with multiorgan dysfunction. Due to the potential for fatal consequences of a severe infection, it is regarded as one of the most dangerous mosquito-borne viral infections in the world. Due to high mortality rate of severe dengue, the development of a quick and sensitive method to predict severe disease early in the progression of infection is of utmost importance. Aim: The aim of this study is to evaluate the utility of DENV NS1 levels as a predictor of severe dengue disease. Results: A total of 126 patients of dengue were included in this study. Day 3 NS1 levels were significantly higher in SD patients as compared to that of DwoWS and DWS patients. NS1 levels (ng/mL) on illness day 3 were a significant predictor of severe disease at a cutoff value of >11009.80 ng/mL with an area under the curve of 0.926 for correctly predicting severe disease. This cutoff value of 11009.80 ng/mL can predict severe dengue with a high sensitivity of 86.7% and an excellent specificity of 94.6%. Conclusion: This study highlights the role of dengue NS1 antigen levels in the manifestations of severe dengue. The performance of NS1 levels (ng/mL) on illness day 3 for predicting severe dengue was outstanding. Day 3 Dengue NS1 levels can be a very good predictor for development of severe dengue later in the course of illness.