HIV is not a game or risks and stats, doesnt matter if you are in the US, Thailand, Haiti, South Africa, use condoms. Besides HIV is not the only STD you need to worry about, there are a lot of other nasty bugs out there. Dont worry yourself over stats, worry that you have a latex with you.
It doesnt matter if you have sex with a GO GO girls, or a 28 ex nun coming out of church if you did it protected,
As rightly said by Teak,, I am concerned about myself when it comes to HIV transmission risk. If I am responsible enough, either use condoms correctly and consistently, or avoid penetrative pleasure with anyone of unknwon status, it hardly bothers me what percentage of women are infected, I had interaction with.
Unprotected sex with anyone of unknown status is dangerous anywhere in the world, including Thailnad.
Use a condom consistently and correctly and you won't have to worry about contracting HIV. Won't matter if the person you had sex with has HIV/AIDS or not.