CD40LG and dengue disease: In studies of severe dengue in urban Sri Lanka (20,22) and in a more recent case-control study of dengue (26), acute dengue was defined by a positive result from a PanBio dual IgM/IgG rapid strip test (PanBio Pty Ltd., Brisbane, Australia) (27), which was performed on a single serum sample obtained on day 7 of illness.