USA HISTORY

Detailed explanation-1: -Along with measles, influenza, chickenpox, bubonic plague, typhus, scarlet fever, pneumonia and malaria, smallpox spelled disaster for Native Americans, who lacked immunity to such diseases.

Detailed explanation-2: -Diseases like smallpox, influenza and measles were in fact the deadly inheritance of the Eurasian farming tradition – the product of thousands of years spent farming livestock. These epidemic Eurasian diseases flourished in dense communities and tended to explode in sudden, overwhelming spates of infection and death.

Detailed explanation-3: -Europeans had spent more time living in close proximity to one another and with animals. This meant that had been more opportunities for diseases to evolve in European society than in the Americas, hence the assymetry.

Detailed explanation-4: -One notable infectious disease of American origin is syphilis. Aside from that, most of the major infectious diseases known today originated in the Old World (Africa, Asia, and Europe).