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Worst Outbreaks of All Time

24/7 Wall St. Logo By John Harrington of 24/7 Wall St. | Slide 1 of 21: Outbreaks of disease have had a profound effect on human existence. From the time of the pharaohs to the present day, epidemics of diseases like the bubonic plague, cholera, influenza, and smallpox have had a cataclysmic impact on civilizations. These scourges changed history, accelerated the decline of empires, decimated armies, and molded cultures. One such outbreak occurred 100 years ago. Just as World War I was ending, the Spanish flu devastated nations all around the world, killing about 20 million people by some estimates. To mark the anniversary of this event, 24/7 Wall St. has compiled a list of the worst outbreaks of all time.

Outbreaks of disease have had a profound effect on human existence. From the time of the pharaohs to the present day, epidemics of diseases like the bubonic plague, cholera, influenza, and smallpox have had a cataclysmic impact on civilizations. These scourges changed history, accelerated the decline of empires, decimated armies, and molded cultures.

One such outbreak occurred 100 years ago. Just as World War I was ending, the Spanish flu devastated nations all around the world, killing about 20 million people by some estimates.

To mark the anniversary of this event, 24/7 Wall St. has compiled a list of the worst outbreaks of all time. Click through the slideshow above to see them.

© Hulton Archive / Getty Images

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