In the case of some of the younger vets, we're interviewing their parents. At our clinic we are treating the spouses but usually not the children, because that's a specialized service we would refer out. However, we may see the family and assess them.
As for the question of whether or not PTSD can be transferred to somebody else, I probably wouldn't say that the other person has PTSD, but that person might be suffering similar symptoms. For example, a way to explain it would be that if the individual with PTSD jumps or becomes very angry every time he or she hears a loud noise, then the people in that person's environment will quickly learn to expect something if they hear a loud noise, so they become nervous and jumpy regarding their surroundings. It doesn't necessarily mean they have PTSD, because if you remove them from that situation, their level of anxiety may well decrease. Yes, they may be suffering anxiety disorders or depression, but I wouldn't necessarily call it PTSD.