Extremely quick! First you need to understand HIV infection rate (
CDC HIV and Transgender Communities) then understand that the neovagina doesn't have tissue as thick as a real womans, thus increasing the risk exponentially. Once you understand that, you then need to understand Hormones, you see these individuals are on Hormone blockers, that puts a lot of stress on the Liver, it's one reason why PrEP is less effective in troons that normal folk in HIV prevention. Anyways when infected with HIV Tenofovir is given usually to reduce viral load, the shit is so powerful though, and coupled with the other drug cocktails, you're looking at Acute Renal failure, Liver failure, and a slow destruction of the CNS (Centeral Nervous System).
The LGBT community never talks long term damage of having HIV, just "Oh, it's not a death sentence anymore" say that to Robert down the street who's been prescribed Tenofovir for HIV and walks like he has parkinson's due to nerve damage caused by the drug. What's even worse, in California they downgraded intentional HIV transmission from a Federal crime to misdemeanor WTF!