Fletcher Infection is a skill located in the Animal Companions (which can be found in the Warden skill tree). Fletcher Infection is a morph of Swarm.
Fletcher Infection deals the following types of damage: Magic Damage. Which means that it gets buffed by the following blue champion point trees: Elemental Expert, Elf Born, Spell Erosion, Thaumaturge. Also the following red champion point trees protect against this skill: Elemental Defender, Thick Skinned.