I transferred a Lucario along with a Pokerus Swampert to Pokemon Y through Pokebank. There is a purple " '-' " next to the markings on both of them, and they gave the rest of my party Pokerus when I fought wild Pokemon. Is this something I can repeat to give other Pokemon permanent Pokerus?
I think this is what you're looking for.
Pokérus may spread if an infected Pokémon is in the player's party after a battle. Pokérus may only spread to a Pokémon directly adjacent to an already infected Pokémon and only if they have never had Pokérus before. From Generation III onward, Eggs may catch Pokérus like any other Pokémon.
Due to the beneficial nature of Pokérus, players will often place an infected Pokémon in the PC where it will keep the infection indefinitely, so that it may be withdrawn to spread the virus at will.
Once a Pokémon's immune system has fought off the virus, they cannot spread it further, nor can it be spread to them by other Pokémon. In Generations II and III, a dot will appear on the Pokémon's status screen to indicate that they have had the virus previously, while in Generation IV and onward, it will be a small face. Though the virus is gone, the Pokémon will still gain twice the EVs it would have gained before the virus.
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