When smallpox struck the Aztec empire, the indigenous population had no resistance to infection from the virus, and was consequently decimated by it. Smallpox wiped out half the empire; even the Aztec ruler Cuitlahuac succumbed to the disease.
天花傳入阿茲特克帝國後，面對這種全然陌生的微生物感染，當地族群完全沒有抗體，只能任其宰割。天花病毒屠戮了半個阿茲特克帝國，連皇帝都難逃一劫。