Has anyone ever seen anything like this? The damaged area was on both sides of this bass. Parasite? Help!

I'd bet that its from somebody catching the fish a while back, holding it there tightly to unhook it and therefore removing the protective slime coating, allowing an infection to form.

Possible, but not many people fish this water. What the heck is the infection? Can it be treated?

Only thing I know to do at that stage Brad is to apply either dry salt or like the "please release me" green powdered formula.
I carry both with me in my boat, if I catch something with wounds I do a dip in livewell and then release-a bit harder when on foot on the move but the dry powder on the wound is worth the effort in my mind.

I may be completely off base, but it kinda looks like where a lamprey eel may have been attached. They usually try to get under the gill plate, but I've seen them on the sides as well.

Being the spots are in almost the exact same place, it does look like a grip spot, tho.

The please release me powder mentioned before does a good job of helping the fish reproduce the slime it needs.