I had not read this. I have read that very early symptoms can include loss of sense of smell, but not that PD "originates" in the nose. "Originate" meaning, to be caused in that region, not be the region that first shows symptoms.

I have, however, read that it might originate in the gut, and in fact that is where Lewy Bodies may first be found.

As for infected cells, I think they take the autologous stem cells out of your bone marrow (usually the hip?), culture them, and then put them back into your body. I don't know that they test them for anything, since if they are coming out of you and going back in....well, you would already have anything the cell might have so what would be the point?