Re: causes of aids

Worldwide, heterosexual sex (vaginal sex) is responsible for the majority of cases of HIV transmission. In the US (and most European countries, depending on whether the countries of the former USSR count), more cases have occured due to men having anal sex with other men. I don't have time right now to go into the reasons for the different patterns.

In terms of what type of sex most efficiently transmits HIV, the answer is receptive anal sex, followed by receptive vaginal sex, followed by insertive anal sex, followed by insertive vaginal sex. The risk from oral sex is minimal. Tweet