You can take away Pokerus, just by not battling for a few days and if you want to know if it went away. Go to your Pokemon status/summary page and see if it has a small frowning face and you'll know that it had went away.
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If you really want to get rid of pokerus, you would need to keep the infected Pokemon in your party (alone, so as to prevent other Pokemon getting infected) for twenty four hours. That said, you really don't want to get rid of pokerus. It's effects are purely beneficial. It doubles the EVs you get from battle, making your Pokemon get stronger faster and making EV training much easier.
You cannot cure Pokerus yourself since once Pokemon are infected with it then they will keep it forever however each new day (up to 4 days) the game will decide whether to cure the infectious nature of Pokerus or not. Pokerus is a good thing to have since it will double the amount of EVs that the infected battling Pokemon will earn when an opponent Pokemon is defeated and as long as it remains contagious it can spread Pokerus to other Pokemon in your party however the game will not get rid of the contagious or infectious nature of Pokerus if the Pokemon is placed in a PC Box.
If you get a Pokerus, then you're very lucky. So keep the Pokemon that you want to get the Pokerus spread to, and keep them in your party. As you travel, the Pokerus will gradually spread to all of the Pokemon in your party. Another great note - If you want every single Pokemon you have to get Pokerus, then keep one Pokemon with Pokerus in your PC Box. I think the Pokerus doesn't go away there, so you can keep on spreading Pokerus to every other!
The Pokerus is not a cheat, but a random status aliment that Pokemon can contract. Obtaining Pokerus is largely random, but can be spread by having a Pokemon with Pokerus in the party with other uninfected Pokemon.
There is no Pokerus in Fire Red , im sorry :(