The correct answer to this open question is the following.
Hernando DeSoto’s Expedition brought disease to the Native Americans. Is there a lesson to learn about diseases that we can apply to our world today?
Yes, there is a lesson.
The first one is that nobody has the right to mess with other nations.
The second one is that people have to be conscious that every part of the world has its customs, traditions, and hygiene practices and these have to be respected.
Native American Indians and Mesoamerican Indians were very clean people. They had notorious hygiene practices. To start with, they used to take a bath daily. They used the rivers to do that.
When the white Europeans arrived, they had tremendous bad hygiene habits. They were no clean people. They did not take a shower daily. And they brought with them several diseases unknown to the Indians. That is why they were not immune to those diseases. We are talking about chickenpox, malaria, smallpox, influenza, and cholera.