Oct 27, 2015 
In the Ebola epidemic sweeping through West Africa, numbers afflicted with the disease are coming close to more than 20,000 people. As a health care professional living in the 21st century, I am of course concerned about all of those infected and hope for their full recovery, but I'm relieved to know that modern medicine is helping people infected with bloodborne pathogens as much as possible. Historically, an epidemic of an infectious disease like Ebola would alter the face of the globe, wiping out populations and spreading across entire continents. Many of these infectious diseases have all but been eradicated, but in their heyday, they wreaked chaos. Let's look at 10 of these deadly pandemics that changed the world.
10. Plague of Athens
We're going old school with the first of our pandemics. In 430 BC, an infectious disease made its way through Athens, which unluckily was also under siege by Sparta (think the movie 300) during the Peloponnesian War. The epidemic lasted three years and infected most of the population of the city-state, an estimated 75,000 to 100,000 people. A quarter of the city's population did not survive, and it was considered such a horrific disease that Athenians commissioned the famous historian Thucydides to carefully document the disease's symptoms and progression to warn future generations about it. Even though this was done, what the actual disease was is a subject of intense debate as forensic anthropological data remains inconclusive.
9. Camp Fever
This illness is known by many names, including jail fever and war fever, but scientifically, it's called typhus. It is an infectious disease that occurs due to unclean, overcrowded living conditions, and it is transferred from person to person by body lice (yeeech). It has reared its ugly head throughout history, most notably during the Napoleonic Wars, the Irish Potato Famine, World War I in Russia, Poland and Romania, and in the concentration camps during World War II. It has been responsible for several million deaths, but now, it is much less common as hygiene standards have improved.
8. Smallpox
Smallpox had been regarded with a healthy amount of fear by Europeans for thousands of years, but it wasn't until it was brought to the New World that this infectious disease became one of the most virulent pandemics. In 1633 and then again in the 1790s, smallpox brought by settlers from Europe ran rampant through Native American tribes in the Northeast, in some cases wiping out up to 70% of a tribe's population at a time. The Native Americans did not have any immune response for the disease, which is why they were so susceptible. Thankfully, this disease has been all but eradicated; the most recent contracted case in the U.S. was in 1949.
7. Asian Flu
Asian flu was a particularly nasty strain of influenza A (also known as H2N2) that took the lives of around 70,000 people between 1957 and 1958. The frightening thing about this particular infectious disease is that it started very quietly, with only a few cases in the late spring early summer of 1957. Once the school year started, children going back to school quickly spread the disease to classmates, who then brought it home to their families. The disease first focused primarily on children, young adults, and pregnant women and was quickly identified due to advances in medical diagnostic testing, and in a few months, it seemed like the Asian flu was gone for good. Unfortunately, a second wave of the disease (which can sometimes happen during a pandemic) broke out, targeting the elderly. This second wave produced the most fatalities, but by the end of the year, the worst was finally over.
6. Tuberculosis
Tuberculosis has been and remains a worldwide pandemic that claims a life every 25 seconds. The World Health Organization estimates that 1.3 million people die every year from this disease. It is an infectious disease that attacks the respiratory system and other organs and destroys body tissue. It is usually transferred through the air by coughing or sneezing. It usually occurs in third world countries and is particularly destructive in areas of the world where HIV/AIDS is present, as it often causes fatalities in populations suffering from this autoimmune disease.
5. The Plague of Justinian
After the fall of the Roman Empire, the biggest power in the ancient world in 527 AD was the Byzantine Empire. The emperor at the time was Justinian, an ambitious man who carried out a number of major building and military initiatives throughout his empire. Unfortunately, there was an outbreak of an unknown infectious disease that swept through the farming and building workforce, quickly racking up a significant body count. It is thought that the disease was a strain of bubonic plague so powerful that once infected, patients barely lasted five days. So many people died from the disease that there were not enough workers and farmers to make enough food for the rest of the empire, and a famine came about as a secondary problem from this incredibly dangerous disease.
4. The Antonine Plague
Speaking of the fall of the Roman Empire, part of the reason for its steady decline was due to the Antonine Plague that flared up in 165 AD under the reign of Marcus Aurelius. The plague took a massive toll on the economy, wiping out government officials, military conscripts, and many others. It also changed the spiritual leanings of the Roman people, allowing monotheistic religions like Christianity and Mithraism to spread. The plague so weakened the Roman Empire that it has been thought that it contributed to the empire's downfall in the 5th century AD. It was thought that the disease responsible was a strain of smallpox, but that has never been confirmed.
3. HIV/AIDS
Beginning in June 1981, a rash of strange infections in homosexual males left at least 121 of them dead by the end of the year. Researchers were unsure of what kind of illness they were dealing with, but the patients all showed incredible susceptibility to certain forms of respiratory problems and a particular form of cancer. By 1982, "AIDS" was first used to describe the autoimmune syndrome when it was discovered that an infant received bloodborne pathogens from an AIDS-infected individual and contracted the same disease; a week later, 22 cases of infant AIDS had been reported. By 1983, there was a large outbreak of AIDS among men and women in central Africa, alerting researchers to the fact that they were also dealing with a sexually transmitted disease. By 2004, the HIV/AIDS pandemic had claimed the lives of 529,113 people, with more than 940,000 cases reported. As of right now, there is no cure but it is the most deadly pandemic in the world, ranking first among the causes of death throughout Africa and certain third world countries, followed closely by tuberculosis.
2. The Spanish Flu
Also known as "la grippe," the Spanish flu killed more people from 1918 to 1919 than all of World War I. It is considered one of the most devastating pandemics ever recorded. It was an unusual strain of influenza that targeted and infected people ages 20 to 40. Normal influenza effects the elderly. At the end of its reign of terror, it had affected the lives of 28% of the entire American population and had killed 675,000 people.
1. The Black Death
During the Middle Ages, around the year 1330, an outbreak of bubonic plague arose in China. As it was one of the busiest trading nations in the world, it was only a matter of time before the disease made its way to Europe, as it was transmitted by rodents and flea bites. In October 1347, a number of Italian merchant ships returned from a trip to the Orient and brought this deadly disease with them. It quickly spread across the European continent, and by August 1348, it had reached as far north as England and was now known as the Black Death due to the unusual black spots that appeared on the infected. On top of its virulence, the plague went on for five years, returning each spring when infected fleas awoke from their dormancy during the winter. The death toll was astounding, killing more than 25 million people, one third of Europe's population. It was without a doubt one of the world's worst pandemics, wiping out entire villages, families, and regions.