They've been able to legally serve, although not out in the open, for 17 years. Why would open service cause wholesale contamination of the military blood supply when it didn't happen during the 17 years when it wasn't knowable who is and is not gay under DADT? I'm not following the logic.
The US military tests individual service members every 2 years for hiv.
Recruiters have been told to aggressively recruit homosexuals.
There are presently 19,000 hiv positive service members.
A person can have hiv for up to 90 days and not test positive on some or all tests. There is much conflict on the accuracy and standardazation of tests. So potentially a medic could have hiv for 2 yrs.3 months and easily pass it on to hundreds of personnel if in a combat situation.
In a mass casualty situation where blood is taken from any and everyone and used immediately or buddy transfusions occur the potential for transmitting hiv is astronomical.