Dieses and pandemics started in the new world because of Spanish aggression combined with new diseases introduced into a vulnerable population of people. Estimates say that after contacting indigenous populations dropped to about 5-6 million which could be about one tenth of the pre contact size. These new diseases were particularly deadly because while combined with the Spaniards colonization of their land, it created a sense of dread into the community. Agriculture and institutions were decimated which made malnutrition and starvation additions to the killer diseases.
Compared to previous diseases we have studied I think that these are the worst because of the situation surrounding its spread into the population. It was almost impossible for the indigenous people to protect their ways of life from the invading European nations because they were so unprepared. They did not know how to deal with these new diseases, and could not get help from the Spaniards. The mistreatment of the people, lack of knowledge of the new sickness, and growing sense of dread prevented them form keeping their culture. It is extremely sad that because of the culmination of all these things massive parts of their culture were completely lost in the following decades and centuries.