When the Europeans travelled to the New World and brought the diseases that wiped out so many Native Americans, why didn’t the local diseases have the same impact on them?

Question

Were the endemic diseases just less severe?

In: Other

Answer 1

There is a chance they did with some diseases. That being said:

The Americas had overal less dense population centres and less lifestock. Diseases could spread so rapidly and effectively in the old world because there were large trading networks and cities to take hold in. Smaller population centre are less sensitive to plagues. They are more likely, but definetly not guaranteed, to burn out before they become problematic.

Lifestock is the other main factor. As happend with covid, swineflu and is now the possible case with birdflu these things develop by jumping from host species to host species. A cold for a bird can become a terrible disease in humans and when it first starts spreading it might only go from animal to human but eventually you get human – human transfer. This is when real fast spreading can begin and it has potential to become a plague.

In the Americas there were native dogs, Lamas, Alpaca’s, some birds and guineapigs. In the old world, herds of cows, sheep, goats, chickens, geese, duck, horses and donkeys etc. etc. etc. were present in large numbers close to humans since ancient times. Often people and animals lived very close to eachother, in the same house or even in the same room. Thats like a petridish for diseases to jump from animal to human.