In many parts of the world, yellow fever is no longer an issue. Yes, some parts of the world still have regular bouts with the disease, but medicine and vaccines have helped with that problem.
Although, not so long ago, the disease was responsible for terrible epidemics. People were forced to flee their homes with the fires still burning.
Scientists estimate that yellow fever originated in Africa around 3,000 B.C. It started with a smaller impact in local villages, growing in range to large cities.