NEW YORK ( TheStreet) -- Fear of ebola has gripped the United States, following the discovery of several cases of the deadly virus in Dallas and New York. Thousands have already died in West Africa during this tragic outbreak but it's not the deadliest disease ever to threaten humanity - not by a long shot.
Still, people aren't scared for nothing. Ebola spreads to an average of two new patients for every one who contracts it. It kills 50% to 90% of those it infects and, worldwide, the disease is far from under control.
In the United States, risk of the infection spreading out of control is low. The public health system is highly advanced and good at handling infectious diseases. Advantages likes working roads, a steady supply of water and other supplies, and morgues to keep the victims from infecting more healthy people should keep the vast majority of the population safe.
Things weren't always this way. In times before disease was fully understood and before effective treatments became available, there were many epidemics that almost wiped out the human race. Even today there are diseases - like ebola, malaria and HIV - that health workers and governments struggle to keep under control.
Here are the 17 deadliest epidemics in history -- click through to see where the current ebola epidemic ranks.
17. Swine Flu - 12,469 dead, 60.8 million infected
The official H1N1 pandemic lasted from April, 2009 until April 2010 and was one of the worst flu outbreaks in modern history. Although the dangers of another Spanish Flu have passed, the swine flu demonstrated that we are still vulnerable.