if you created a recovery disc or USB using DBAR it should only backup the restore partition of your computer, nothing else.  As such when  you install it, you would get a fresh copy of the OS as if you just bought the computer and turned it on so you would not have any of your user files, media, etc.  As for the virus thing, its possible since its on the same hard drive but normally the partition is hidden and locked so I would think the virus would have to target Dell's restore partition or software specifically.  
 Does creating a recovery media in Dell Backup and Recovery backup user data? What if there is a virus infected file?   I created my recovery media, after my computer was infected with a virus. So, I just wanted to know if the virus file is also in the recovery media or not.
Regarding Dell Backup and Recovery