Interest in trail participation was quite high, except for circumcision studies, suggesting, as iPrEx demonstrated, that this is a suitable population for future generations of HIV preventive interventions. Northern Thailand may be a unique context in which to study HIV preventive interventions for Transgender populations.entions among use rates The findings of high HIV prevalence and incidence among these populations of MSM in Chiang Mai are unfortunately consistent with data from other Thai sites, and from the wider Southeast and East Asian region.