get stuck on Ebola

Hey.

I got stuck on Ebola.
May one of the 17 solvers are around here and may give some hint.
I may spoiler a bit down here.

SPOILER

So maybe anyone can give me a little hint.
Thanks so much
paddyg13

You can appoach this challenge using two different paths. Both paths involve the most basic tools of cryptanalysis i.e. counting things, frequency analysis.