RTN Question?

I took the Pagoda Cup ouy of my tank that had RTN even after fragging it, the RTN spread to other area's of the cup, since it had some unseen RTN on the underside where I never thought to even check And I also found some very small white crab's on it. I gently lifted it out of the tank as to not drop any. Hopefully they were isolated.
Is there anything that can be done about RTN except fragging?
Does it spread to other coral's or just wipe out the one that's infected?
I am concerned about a few other coral's, some SPS and Monti Cap's.

 

a good way to determine if anything else will be effected is this-
same genus, same species: most likely
same genus, different species: possibly but not usually
different genus, different species: no, unless they have the same type of tissue

 

and were the crabs copepods? when my acan had rtn my copepods were swarming on the decaying tissue like crazy

 

They were 8 legged 2 pincher ghost white crabs just a little small than the eraser on a number 2 pencil if he were to stretch out. For sure not pod's thanks for everyones input.