Is it due to European trends of living in highly concentrated communities and therefore having developed immunity? Or were there significant differences in the detrimental effects of prevailing 'germs' (for my lack of terminology in the field) in Europe and Central America e.g.?
Hi there -- not discouraging new answers, but this question gets asked a lot here. You may be interested in our FAQ section on Disease in the Americas.
It's a matter of debate but there is strong evidence that Syphilis originated in the Americas.