Bloodthirst doesn't cure anything. Bloodthirst does make some affects go into remission (away, essentially) for a while. Healing curse doesn't stop this.

Ok. Then you might want to change the hex augur echo which says they are cured? Might just not have it say anything at all, since while it's not affecting them anymore temporarily, it's not cured, either. Maybe don't have thirsting trigger the hex augur echo?

I always thought, as high priest, that it was removing plague etc.

Also, I don't remember getting a second echo later when it wore off? As in, if they were plagued, thirsted, then subequently had to deal with it again, I'd expect a second echo when it wore off for good?

bloodthirst does make certain things go away forever specifically anything that does minus str affecting you at the time of the thirsting. (I always wished there was an edge or something to switch that to -dex for dex based ragers)

so yes thirst cures poison and plague since both are one line and just have -str.

If that's true, it's buggy.