Researchers at the International AIDS Conference sifted through published papers on the risk of heterosexual HIV transmission. They say that while a popular estimate pegs the rate of HIV transmission through heterosexual sex at 1 per 1000 contacts, true rates of infectivity are all over the map and dependent on many variables. The infectivity rate for certain sorts of activities is much, much higher-- as high as 1 in 3 contacts. The take away message? "Claims in both the popular media and the peer-reviewed literature that HIV is very difficult to transmit heterosexually are dangerous in any context where the possibility of HIV exposure exists."