I'm not sure about this, but isn't tuberculosis connected to animal husbandry, especially cattle? If my memory serves cattle and cow's milk were primary agents for the spread of tuberculosis in the Victorian era. Since Jews were not allowed to own land in certain areas, or at least were often in cities, they might not have been exposed as often to cows. Was this the case in Poland?
At any rate, kosher rules mandating the separation of milk products and meat products might have cut down on cross contamination. Also, Kosher meat has to be handled in very specific ways. One of the most important aspects of it is that the blood is drained and the meat is salted, but also any blemish, any disease in any of the organs, especially the lungs, and the meat is considered unfit to eat. Might that not cut down on tuberculosis exposure?
http://en.wikipedia.org/wiki/Kashrut
I don't know about smallpox. Didn't dairymaids and other people who worked with cattle often get exposed to cowpox and so developed an immunity to small pox? If many Jews were city dwellers they wouldn't have been working with cattle very much.
That doesn't mean genetic factors might not have been at play.
As to the map above, the lighter areas look as if they might be higher in Neolithic ancestry? Would that make sense in that they'd have more resistance against cattle diseases because they were around them longer?