CD40LG and viral infectious disease: Moreover, for the 48 non-DENV-infected patients, all acute-phase and early convalescent sera were tested for IgM directed against two other flaviviruses (Saint-Louis encephalitis and yellow fever antigen, data not shown), and for the false-positive Panbio result, the paired sera were retested to confirm the absence of cross-reactivity with these two flaviviruses.