The European conquest of the New World was not caused by guns, swords, or barbaric type behavior but by the invisible danger-germs. Infectious diseases have played a major role in shaping the conquest of the New World. Vast amounts of people indigenous to the Americas died due to various types of diseases.
Most infectious diseases result from a microparasite.
Their short generation time and size characterize them. Microparasites also go through two stages until an infection leads to a disease. The period from the point of infection to the appearance of symptoms is termed the incubation stage. At this stage, symptoms may not be extremely prevalent, and the person can infect others. The incubation period is the most critical stage, because the microparisite is lying dormant, and unknowingly the disease can be spread.