Ding! Someone is using their grey matter.

Anyone ever wonder what happened to that really great paper that came out of Rice University which proved that "Gulf War Syndrome" had components of the AIDS virus written in the RNA of the virus that caused GWS? Yeah, it disappeared, along with the researchers who discovered it. If I had known then, I would have had a printer and printed that bastard as soon as I found it.

To put it simply, the AIDS virus was encoded into the RNA of a virus. You can do it to any virus say the common cold. Just take out what you don't need, add some genetic material into the RNA part of the virus, and infect someone with it. The new messages from the RNA of the virus then bonds to their DNA. Isn't that great? Generations of infected people every time one of those soldiers or their progeny have a baby.