Okay, there is no risk of contamination in anything because there is no proven disease. Kirkman says in the above link on zombies that a zombie's bite kills because of a lethal infection, just like if you let a cut get infected. Infected doesn't imply a zombie strain, just contaminants in the air.
A zombie's bite is NOT always lethal. Dale is a bite survivor. There was one other...he bled out though.