H/t to Instapundit, here is an article on a horrible parasitic disease in Africa.
Aren’t the cold and snows of the northern latitudes a hostile environment for man? To an extent, yes. But the tropics have both large predators, such as lions and tigers, and large grazing animals like elephants that won’t eat you but will stomp all over your crops and knock down whatever fence or wall you might put up.
Even worse, microscopic parasites, bacteria and viruses attack the human body mercilessly. The death rate for Europeans in the tropics before modern medicine was astronomical, and even today it’s unhealthy and dangerous.
We have to remember that Africans are simply adapted to a much different environment than Europeans or northern Asians. Their adaptions simply do not transfer to environments outside sub-Saharan Africa, a relatively small and isolated part of the earth.