These videos, on the reason there was no spread of plague from the New World to the Old, and why so few animals are easy to domesticate, may please and enlighten you. I commend them to you, sirrah.

http://www.cgpgrey.com/blog/americapox

http://www.cgpgrey.com/blog/zebra-vs-horses-americapox-part-2

The basic theory being that the reason Europeans took over the world is because they were dealt a better set of cards when the game commenced.

There are a few, a very few straightforward errors in this. One is that London was the cholera capital of the world. It wasn’t. Another error is that plagues are transmitted by animals. They may jump from animals to humans but they are transmitted by humans not animals.

The article also misses, unless I’ve misread, several possibilities. One is that diseases and humans evolved together, but humans so recently arrived in America, only during the ice ages.

Another is that precolumbian Europe was genetically diverse whereas America was genetically uniform, making plagues spread faster.

A third that the article fails to mention is that the transfer of serious diseases to Europe from America would have been masked by the transfer there of diseases from Africa and India and Asia that were happening at the same time due to other European explorations.