Because Europeans don't gun down people in the street and bayonet babies, like the Chinese and Japs and Mohammedians do, when they are on about a mass killing.

So many survivors? Well, because the churn at the camps. Survival was less than a year or so, but hey, if fresh prisoners are always coming in and the camps held a lot of people, there will be survivors and lots of them.

As for giving them medicine, I am admittedly ignorant about that, other than wouldn't that be better saved for troops?