hope your not using backups to reinstall info 'cause your just reintroducing the virus again. guess it would depend on if your networked and have any sort of replication going on.
Sometimes formatting will remove the virus, sometimes not. I'd definately say you should have REPARTITIONED just to make sure. That's what i always do so that there is no chance that it could be hiding in the MBR or small remants on the Hard drive. Because once you destroy and recreate partitions, you completely wipe everything out.