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.

16. The Moscow Plague - 50,000 to 100,000 dead

An outbreak of the bubonic plague in 1770 Moscow killed up to one third of the city's inhabitants. It caused riots and food shortages before the government could finally get it under control.

15. Ebola Outbreak of 2014 - 4,922 dead, 10,141 infected 

While Ebola has proven less dangerous to Americans than hedgehogs, in West Africa it's a different story. Since the outbreak began in March it has claimed nearly 5,000 lives and continues to spread.

14. The Great Plague of London - 100,000 dead

This last known incident of the Plague in London killed nearly a fifth of its population from 1665 - 1666.

13. The Plague of Athens - killed up to 30% of ancient Athens 

Little is known about the Plague of Athens which broke out around 430 B.C., during the Peloponnesian War. What we do know comes courtesy of the historian Thucydides who reported that it arrived from Ethiopia and killed between one in three or four Athenians. Today doctors agree that it was likely either smallpox or typhus.

12. World War I Typhoid Outbreak - more than three million dead

Typhus outbreaks are driven by poor sanitation and overcrowding, making them common during wartime.

11. The Second Pandemic 1827 - 1832 - more than 100,000 dead, as high as 70% mortality 

This cholera outbreak is considered one of the first modern pandemics by many scholars. Originally a tropical disease, this first terrified Europe during the Second Pandemic when British colonial troops brought it home from India, even inspiring some of the first survivor fiction with the eerie beginning to the novel The Secret Garden.

10. The Third Pandemic - 10 million dead over 100 years
An outbreak of the bubonic plague that lasted nearly 100 years, the Third Pandemic began in the Yunnan province of China in 1855 and wasn't declared over until 1959.

9. The Great White Plague - 17th Century Europe's leading cause of death

Mycobacterium Tuberculosis bacteria have been found as far back as Egyptian mummies, and in the 1600's it started Europe's Great White Plague that killed nearly one seventh of its victims for nearly 200 years.

8. The Shakespearean Smallpox Epidemic - 25% of London dead

One of the worst outbreaks of smallpox ever hit London in 1563 wiping out a quarter of its population and shutting down all the theaters.

7. The Antonine Plague - 5 million dead 

An outbreak of either smallpox or the measles in ancient Rome, records indicate that it killed nearly five million citizens in the capital city including two emperors, nearly one third of the population.

6. The Plague of Justinian - 40% of Constantinople and perhaps up to 100 million dead

Thought to be a form of the bubonic virus this pandemic hit Constantinople particularly hard, killing 40 percent of the city's population and wiping out nearly a quarter of the Mediterranean world's population.

5. Malaria, Current Outbreak - 200 million infected, 627,000 dead annually

Heartbreakingly preventable Malaria is ripping through sub-Saharan Africa where it infects hundreds of millions of people a year in an ongoing outbreak that is only getting worse despite the disease's proven vulnerability to mosquito nets and the antibiotic doxycycline.

4. HIV, the first outbreak - 36 million dead 

While HIV is far more treatable than it once was, approximately 35 million people are infected by this virus and many go without the most effective medicines.

3. The Spanish Flu - 50 million dead, 40% of humanity infected

One of the worst plagues in human history, the Spanish Flu was so bad that it cut the average U.S. lifespan by 10 years in its trip around the world.

2. Various Smallpox Epidemics - 500 million people in the 20th century, as high as 90% of Native Americans in pre-colonial times, 400,000 a year in Europe during the 18th century 

Smallpox has been evident in human populations for more than 10,000 years and has been a leading cause of death and blindness. When European explorers reached the New World they brought a plague for which the natives had no antibodies. Its devastating impact allowed small groups of settlers to conquer an entire continent.

1. The Plague - 75 Million Dead

The Black Death claimed 75 million people at a time when humanity numbered far less than it does today. It exterminated more than one-third of Europe's population.