Final answer:
Native Americans were severely impacted by diseases such as smallpox, influenza, measles, and typhus after European contact, due to having no prior immunity.
Step-by-step explanation:
The types of diseases that devastated Native American populations after contact with Europeans included smallpox, influenza, measles, and typhus. These diseases were often brought to the Americas by European explorers and colonists who had developed some immunity to them; however, Native American populations had no prior exposure or natural immunity, leading to widespread outbreaks and fatalities. The introduction of these diseases was accidental and was a significant factor in the dramatic decline of the native populations.