Globalization and disease Eurasian diseases to the Americas was that many more native peoples were killed by disease and germs than by the colonists' use of guns or other weapons. Scholars estimate that over a period of four centuries, epidemic diseases wiped out as much as 90 percent of the American indigenous populations. In Europe during the age of exploration, diseases such as smallpox, measles and tuberculosis (TB) had already been introduced centuries before through trade with Asia and Africa. People had developed some antibodies to these and other diseases from the Eurasian continent. When the Europeans traveled to new lands, they carried
A Short Account of the Destruction of the Indies been accused by many scholars about making exaggerated claims in terms of the death toll and mistreatment of the indigenous people. Today, it is known that Old World diseases and the lack of immunity caused a large number of indigenous deaths. The reason why De Las Casas did not mention the number of indigenous deaths caused by old world diseases is not a political one. During the 1400s, people did not know what caused disease or how it spread. The discovery of germs wasn't until the 1500s, and their association with diseases was not even accepted by the medical profession