It's pretty clear that AIDS and other sexually transmitted diseases spread just as well from almost any kind sexual activity, and many of them -- including AIDS -- spread from any transfer of bodily fluids at all.
It's clear that HIV can spread via a wide range of sexual activities, but some are much higher risk than others. At the extremes, receptive anal intercourse has a transmission risk roughly 50 times higher than insertive vaginal intercourse, while the risk of oral sex is believed to be non-zero but too low to be accurately measurable.
Wikipedia gives estimates on differences between anal and vaginal transmission are about 8-1 but also admits the numbers could be off by a factor of 10.
What we know is that the AIDS epidemic was at it's worst in Africa where it was largely spread through heterosexual transmission.
It's clear that HIV can spread via a wide range of sexual activities, but some are much higher risk than others. At the extremes, receptive anal intercourse has a transmission risk roughly 50 times higher than insertive vaginal intercourse, while the risk of oral sex is believed to be non-zero but too low to be accurately measurable.