An article from Thai Guru may interest some readers here. Apparently, the subtype of HIV most common in Thailand is much more contagious than the subtype generally found in the West. Subtype B, which is most common in Western countries, has a female-male transmission rate of approximately 5 in 10,000 exposures. But subtype e, which is most common in Thailand, has a female-male transmission rate of 1 in 30 to 1 in 50 exposures. That's a huge difference.

Here's an interesting excerpt:

One of the best medical web research sites (geared for physicians) has an in-depth research report conducted in Thailand, which reports: "One of the earliest studies suggesting differences in efficiency of transmission among HIV-1 subtypes was a cross-sectional seroprevalence study of HIV-1, presumed subtype E, in Thai military conscripts infected by commercial sex workers (CSWs). Using mathematical modeling, researchers estimated that the probability of female-to-male HIV-1 transmission per sexual contact was approximately 1 in 30 to 50 contacts; previous estimates for HIV-1 subtype B were estimated at 1 in 500 to 1000 contacts.

Full article here:

http://www.thailandguru.com/health-hiv.html

Has anyone else read anything similar? Apologies if this has been discussed before.

Certainly read something before about the sub-type most prevalent in Thailand being more contagious.

The mathmatical modelling notion does raise questions though - they have been so wrong about HIV and other diseases in the past using mathmatical modelling - what they need is real life clinical studies with enough of a sample size to make it significant.