Pokerus = Macho Brace except that it doesn't last for ever... and u can obtain Pokerus by getting a Pokerus'd pokemon from the GTS, or tell a hacker on these forums to make u a pokemon that has pokerus, then when the pokemon with PKRus is in ur party, all of ur party members will automaticly get it for sometime
You can check heir summary to see if they have it or not
Then after a while when pokerus is gone, ur pokemon will be immune to it and you will see a smiley face beside their picture in Summary.
Hope that helps
Edit: Oh, to get Macho Brace is ofc get someone to hack it for u (easy way)
or collect all 3 Burmys and show it some some niggah... he lives in... idk i forgot
When Pokerus wears off a pokemon, they get a little happy face icon. They still get the double EV's even after Pokerus has worn off.