I wouldn't say "many" a portion but the body can carry every form of bacteria and every from of virus. we know blood is a wonderfull petri dish for incubating and proliferating micro organism...and giving that chance to breed and adapt is just the reason why AIDS exist.
Except that viruses are not counted technically as micro-organisms. And blood is not a wonderful petri dish inside the body, though outside maybe, until it dries.
Then what is a virus? And why does blood carry the highest risk of contamination along side sexual contact?