All nonmagical food and drink within a 5-foot radius sphere centered on a point of your choice within range is contaminated with your choice of one of the following diseases or poisons: assassin’s blood, cackle fever, sewer plague, sight rot, or truth serum. The food and drink remains contaminated for the duration of the spell, after which time it is no longer a vector for the chosen disease or poison. A creature who ingests food or drink contaminated in this way must succeed on the saving throw called for in the disease or poison’s description, using your spell save DC instead of the normal save DC for that disease or poison. These diseases and poisons are detailed in Chapter 8 of the Dungeon Master’s Guide.