Recent approaches using multivariable logistic or linear regression models have shown that petechiae, thrombocytopenia (platelet count #100,000 cells/mm 3 ), positive tourniquet test, rash, and other signs and symptoms can distinguish dengue from OFIs [11] [12] [13] [14] [15] [16] [17] ; however, results were not consistent across studies. Only two studies considered clinical and laboratory features according to day of illness [18] [19] [20] , but as these were hospital-based studies, the results likely reflect patients with more severe symptoms and not the clinical spectrum of all symptomatic cases in dengue-endemic populations. Furthermore, none of these studies analyzed data using longitudinal statistical methods, which account for correlations between repeated measures on individuals over time. The use of longitudinal statistical methods to analyze cohort data is essential to utilize all of the data available for analysis and appropriately estimate the within-person and betweenperson variance in measures over time.