A while back I saw, what I assume was a military cover-up story, like this one, where they claimed
Vietnam vets got hep C from either drug use or prostitutes in
Vietnam.
Many vets from that era, including some of our members on the forum, will tell you stories about the air-jet gun inoculations. They were so sharp, that if you moved slightly, they cut you. The men were lined up, and each were given a shot, without cleaning the gun in-between.