Probably many. Nobody had any resistance to diseases from either landmass, so even the common cold corona viruses probably wiped the floor of the Americas. Smallpox kicked the shit out of everyone, as did measles, and malaria always kicks the crap out of people too, though that might have been native to the Americas already.
New diseases were also introduced to Europe, though the severity was probably much lower. One of the STDs is a new world disease, though I forget which one. I think it’s syphilis.
Probably many. Nobody had any resistance to diseases from either landmass, so even the common cold corona viruses probably wiped the floor of the Americas. Smallpox kicked the shit out of everyone, as did measles, and malaria always kicks the crap out of people too, though that might have been native to the Americas already.
New diseases were also introduced to Europe, though the severity was probably much lower. One of the STDs is a new world disease, though I forget which one. I think it’s syphilis.