Cholera flourishes today because of dense, stable housing with poor sanitation, which were lesser problems for hunter-gatherers. (Not to say that cholera wasn'

Cholera flourishes today because of dense, stable housing with poor sanitation, which were lesser problems for hunter-gatherers. (Not to say that cholera wasn't still a killer...) Properly cooking and cleaning food (and avoiding having to eat raw food) are really important factors, though.