CD40LG and dengue disease: The reduced sensitivity of NS1 assays for DENV-2 infected patients could in part be related to the serological response in these individuals; there was a statistically non-significant trend towards more secondary dengue in patients with DENV-2 (85%) than either DENV-1 (76%) or DENV-3 (73%) (P = 0.36) and a relatively greater proportion of DENV-2 infected patients had measurable DENV reactive IgG (Fig. 3B), rather than IgM (Fig. 3C), in the test sample.