To establish eligibility for inclusion in a phase @b , randomised , double-blind , placebo-controlled , proof-of-concept trial , individuals aged @-@ years who had had a fever ( @C ) for less than @ h , met at least two criteria indicating probable dengue infection , and had a positive result on a dengue point-of-care test kit or PCR assay were referred for screening at a centre in Singapore between July @ , @ , and March @ , @ .