I go to the gay night pub, and there're many people on the dance floor. While dancing, I'm scratched by the others' nail -- it's no bleeding, just scratch; anyway I'm not sure that it's bleeding or not --as I look at my arm and hand, I don't see the bleeding on them. Also, I shake hand with one guy and I know that hiv transmittion doesn't occur through causal contact, but I'm worried that there may be little wound or sore on my hand and his hand. If so, will I be infected? Then, he hugs me from my back and dance with me -- I don't notice that there're any blooding on his arms or not at that time, but being worried after that when I arrive home. I'm worried of these questions, help me please. Sorry for the questions that seems rediculous, but I'm really afraid because I think hiv is high risk in gay group. T________T"