You'll just have to keep everyone separated. I rescue dogs, but I don't let any newcomers intermingle with everyone else right away. First it has to be vet checked to rule out anything contagious. (My dogs and fosters are current on vaccinations, but nothing is full proof.) Then I have to evaluate the dog's temperament and personality, get to know it myself so that I know how it will react in different situations.

Since this dog has been through a lot, the most important thing you need to worry about right now is getting the dog to trust you. If you manage to get the dog to your house, you don't want to overwhelm him with too much at once, so just keep him by himself. If you have other dogs the link below will give you tips how to deal with that:

http://www.pbrc.net/rotate.html