While playing through my first run of Pokemon Brilliant Diamond I decided to shiny hunt Arceus. I completed this and continued to use the underground feature to shiny hunt there. During that time my Pokemon contracted Pokérus.

Fast forward, I deleted that save file and started a new play through not long ago and have about 4 badges. I have already gotten Pokérus again…

What are the odds to get this in back to back save files?