People have fought a variety of infectious, fatal diseases throughout human history. Even those diseases that are now entirely curable were once even more terrible before the 20thcentury discoveries in virology and medicines!
Even while these transmissible illnesses have been around from the time that humans were hunter-gatherers, things really started to deteriorate when people started to settle down.
Smallpox, influenza, TB, and other ailments first surfaced. We humans have persisted despite each outbreak of these diseases, though! And each time, our understanding of how to handle them grew as well.
Here are 9 fatal diseases that altered history and medicine for all time.
[NOTE: Non-communicable conditions like cancer, diabetes, and heart disease are some of the illnesses that claim the most lives. However, they have not been incorporated because they are not contagious.]