There has been a question bothering me for some time. I did already some research but couldn't find a correct answer.
I've read that the risk of getting HIV by jerking each other (man&man) is negligible. Also docking and frottage, where precum (or even cum) gets in contact with your or the other one's urethra, would be a negligible risk?

Now I'm wondering... Why is there such a bigger risk envolved with anal sex? Because the dick (and urethra) of the top boy also gets in contact with blood that contains HIV. It's about the same risk you do as with jerking each other, right? Because also fluids that contain HIV gets in contact with the urethra.

I've also read that still while jerking each other, there is a negligible risk that you get infected if your partner rubs precum or sperm on the urethra. Or is this totally wrong? If correct... Why is anal sex then such a bigger risk? Because it's about the same... Blood that gets in contact with your urethra.

The main question I don't understand is how a top can get infected. Because people are saying that the urethra is no way to get infected?

Thanks in advance

Hello and thanks for reaching out to the AIDS Vancouver Helpline with you question.

It seems you want to know why different kinds of sex acts are categorized at different levels of risks. We will be glad to provide some information.

1. The following transmission equation would help us to explain some of the following points so let us start there. For HIV to transmit there has to be the following:


---------- -------- ----------------------------
• blood (including menstrual) • unprotected anal or vaginal intercourse • vagina
• semen • sharing needles • anus
• pre-cum • mother to child (in specific cases) • urethra in the penis
• rectal secretions • open cuts and sores (in theory)
• vaginal fluids • other mucosal membranes
• breast milk • points of needle injection
There has to be a body fluid which carries the HIV and this must have direct access into a bloodstream through some activity without being exposed to air. Now that we have made this clear let us respond to your specific questions.

2. Jerking although it involves body fluids is regarded as a No Risk activity. This is because the body fluids involved have no direct access to the other person's blood stream.

3. Docking and frottage are considered activities of Negligible Risk. This means that although they involve body fluids there has never been a confirmed report of HIV transmission by these activities.

4. Unprotected anal sex is considered High Risk because it involves body fluids that are not exposed to air and have direct access to the mucus membrane of both parties. Mucus membranes have loosely packed cells and have no keratin layer to protect against infection. A significant number of scientific studies have repeatedly associated the activity with HIV infection.

5. When HIV is exposed to air it is no longer transmittable. Rubbing precum exposes the fluid to air and any HIV that might be present.

So the points to note here are that when body fluid is exposed to air then any HIV it contains is not transmittable. With anal sex there is a lot of body fluids involved and a large surface area that can be the entry point that is why it is considered a high risk as compared to rubbing precum.

Additional information on HIV risk and the biology of HIV transmission can be obtained from the following articles. The [Canadian Aids Society]($FILE/HIV_Transmission_Factors_that_Affect_Biological_Risk.pdf), and [smart sex resource]( If you have additional questions feel free to contact us again.

Thank you for contacting the AIDS Vancouver Helpline.


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