In the present paper, we have prospectively evaluated three diagnostic methodologies (IgM antibody ELISA, NS-1 antigen ELISA, and real-time reverse transcriptase [rRT]-PCR) for the detection of dengue virus infection in patients presenting with undifferentiated fever in a dengue endemic area, with the aim of determining the optimal acute specimen testing strategy in a routine clinical setting. Here, CD40LG is linked to dengue disease.