I am very curious if one can catch HIV from objects used by HIV-positive people. There is one time, in a restroom, I asked a stranger for paper towels because there is no paper towels in my cell. He gave me the paper towels, and then I used it to wipe my anus, after wiping, I found that there is some blood the paper probably because I wiped too hard. Is there a risk in such situation? Would there be any factor that can increase the risk in such a situation? Thanks.