Radius of effect for Epidemic?

Ive been trying to use epidemic along with Enervating Charge, which causes weakness, which is a condition I believe. However it doesnt have a visual cue, so I dont know if my epidemic is spreading it at all and how far away. Can someone enlighten me on the radius that Epidemic will spread?

it is about the size of searing heat

O ok thanks. Once i get searing heat ill go check it out.