Seems a little naive in your confusion as to why the military would care or try and help. I'm not sure if you watch TWD and remember the flashback scene of Shane in the hospital where Rick is? Or played Halflife. Or any other game or TV show or movie ever involving any quarantine event and the military? When we finally add the military soliders doing clean up sweeps into the game, are you going to run up to them going 'thank god you're here!'?
Suffice as to say the people in the helicopter, whatever they are doing, aren't out on a mission looking for survivors to help out.
That makes sense, and each time you could get like an extra 1-5% chance of getting it correct.
The more time you spend examining the clearer the picture you would get.
Also you might want to see this post too if you like medical ideas!
He has some great ideas too!