he had dried blood on his hands but does donate plasma...

About 2 weeks ago, my uncle was playing basketball and the backboard fell on him, gashing his eye considerably. He was stitched up at the hospital and sent home (he stays with my parents and I). The next day, he asked me whether or not I wanted his leftover barbecued chicken (it was cold) that my cousin had prepared the previous day. I stated that I did, and ate the chicken; afterwards, it dawned on me that perhaps he had dried blood on his hands. Although he didn't have dried blood on his hands when I asked him (I looked myself in a very subtle way), when I asked him about an hour later if he had any dried blood on his fingertips/cuticles, he said that he did. Also, I have two broken teeth, one of which is pretty much gone, save the roots, and my gums bleed on occasion. Now I am very scared that I may have been infected with the HIV. Do you think that his blood was in the chicken? Also, he donates plasma (twice this week), and they screen it for HIV (so I heard). Thank you.