Dear professor:
thank you very much for your so rapid response which makes me feel so relaxed .
the reason i am so irrationally concerned about those zero risk situation is there are so many chinese doctors without conscience.some of them tell us that HIV can be transmitted by mutual masturbation if the person giving you masturbation has a drop of blood on his hand ,they also say that I can catch HIV by geting scratched if there is a drop of blood on his finger or nail.first I trust those words and it really freaked me out.on june I made a trip to US and saw how develloped US is so now I only trust experts of U S, I am so glad I just had a chance of talking with you ,a leading expert on HIV ,now I feel good ,thanks again ,you are doing a great work to people in need !
best regards
Welcome to the forum.
This question and your two recent ones on the HIV community forum indicate that you are irrationally concerned about HIV transmission through casual contact. The virus is transmitted sexually, which means intercourse (a bare penis, no condom, inside another person's vagina, rectum or rarely mouth) or by sharing blood overtly, as by sharing injection equipment. It is never transmitted by other skin to skin contact, oral contact, contaminated environments, or scratching. Everybody knows this and you should not have to ask about it. The biological reason is that for transmission to occur, large amounts of virus must have contact with just the right type of body cells. The sorts of events you have been asking about simply do not involve enough virus in contact with the right kinds of cells.
Do your best to stop worrying about such things. If you don't have unprotected intercourse with new or casual partners, and if you don't share drug injection equipment, you will never catch HIV. Period.
Best wishes-- HHH, MD