Nope. Pokerus lasts for 2 Days (INCLUDING when the game is off!!), but that time is frozen in the PC, so not only does it keep it, while it remains in the PC it will never lose it. It is passed on to other pokes by winning battles with the infected pokemon somehwere in the party (it need never actually participate in the battle).
I always keep about 15 or so weak pokes like the ones I traded to you infected so I don't lose it.
I always keep about 15 or so weak pokes like the ones I traded to you infected so I don't lose it.