Women are at greater risk as after sex infected semen stays longer inside the vagina and there is plenty of time for the virus to pass through the membrane into the blood. However, this does not mean that men are not at risk. The skin of the penis is very thin. Moreover, during anal intercourse (between a man and a man, man and a woman) there is a particularly a very high exposure as the anal passage is very tight and there are chances of cuts and wounds through which the virus can enter the body. A condom is effective in preventing HIV transmission during any kind of penetrative sexual activity.
