In a conversation today with a virologist from NCI I was told that a blood sample could show only antibodies to HPV, meaning that at some point in your past you had an HPV infection. The antibodies are there forever. The antibodies can be sorted by strain of HPV. But since we do not know for sure if it goes dormant in your body and becomes active sometime down the road, or even multiple times down the road - or if you just get re-infected with it over and over because it is so common, there is no blood test to detect an active HPV infection. So an in situ hybridization catalyzed signal amplification test on a group of cells is the gold standard for finding it, and identifying type. The issue is where to collect it from in the mouth if there is no actual lesion to capture it from.