What would YOU do with it? Don't know what pokerus is? I will give a brief explanation for those who don't know: pokerus is a disease in pokemon, that like most diseases, spreads. The big point of pokerus is that is doubles the EVs your pokemon gain after a battle. Don't know what EVs are? Look it up. How rare is pokerus? Your chances each battle(and that's if you battle, not run or use repel) of your pokemon contracting the virus is nearly 1 in 22000! A (wild) shiny pokemon chance is 1 in 8193!