11 Biggest Epidemics in Human History

These 11 biggest epidemics in human history are responsible for more than 220 million deaths and an untold amount of misery.

Rarely a year goes by that some new disease – or a mutation of an old one – doesn’t get trumped up by the media as the next Black Death. Hantavirus, Ebola virus, and the Zika virus are just a few of the exotic names we hear on TV, followed by the dramatic prognosis of worldwide pandemics. Every year a new flu mutation occurs, sending scientists scrambling to devise a new vaccine that will stop it. Hollywood adds to the mix its own angle, with a veritable flood of zombie movies and TV shows, showings us what grim future awaits us.

While none of those viruses are among the Most Deadly Diseases in the World Today, they can be fatal and in parts of the world affected by them people die and suffer. But compared to millions killed by the biggest epidemics in human history, they pale in comparison. Those have largely faded from human memories and remain confined to history books. The anti-vaccination movement is an excellent example of just how fragile human memory is. Despite being eliminated in the United States in 2010 and being on the decline worldwide since the 1960s and the introduction of the vaccine, measles (as well as other Deadly Diseases Cured in the 20th Century) are making a comeback. Ironically, this time the most developed countries are affected since the anti-vaccine movement is the strongest there. There are no anti-vaxxers in Africa, India, or any other place where people remember children dying from preventable diseases.

One of the greatest catastrophes in human history was the introduction of European diseases to the Americas. Measles, smallpox, influenza, even bubonic plague devastated the native population in both North and South America, leaving millions of dead in their wake. Unfortunately, there aren’t any record indication just how many people each of those diseases killed, so we decided to leave it out of the list and instead mention it here, with two exceptions you’ll find further down the list.

We tried to find credible sources for each of the 11 biggest epidemics in human history and have provided a link for each source. However, it should be clear that for the most part, the epidemics death tolls are just estimates, albeit highly educated ones and made by the experts. The true number of deaths for the Black Death or Justinian Plague will never be known since the precise records weren’t kept and sources we have can be very unreliable. Even the reliable ones could hardly have had the information for anything going on outside their cities, or how many peasants have died from the plague in some far-flung corner of the Empire. Here is our review of the 11 biggest epidemics in human history:

11. Russian Flu

Death toll: 1 million
Year: 1889–90

This is the first of the big influenza epidemics that ravaged the modern world. It was also the first epidemic in a world that was connected and an extensive railroad network helped spread the disease immensely. The deadly virus only took four months to reach to New York from St. Petersburgh. For a long time, it was believed that the virus in question was H2N2 of the Influenza A, but recent studies suggest that it was the H3N8 strain that was responsible.

11. Sixth Cholera Pandemics

Death toll: 1.3 million
Year: 1899–1923

The sixth cholera pandemics broke out in India in 1899. It killed about 800,000 people there and additional 500,000 in Europe, Middle East, and North Africa. Russia was especially hit hard, but not as hard as in 1852 pandemics.

10. Asian flu

Death toll: 1.5 million
Year: 1957

Asian flu originated in China in early 1957. By summer it reached the continental United States. At first, it didn’t look all that serious, but then a second wave hit. By March 1958, almost 70,000 people in the United States alone died. Worldwide, about 1.5 million people lost their lives to the culprit, Influenza A subtype H2N2.

9. Third Cholera Pandemics

Death toll: 1.5 million
Year: 1852–60

In 1852, a new cholera outbreak, that was one of the biggest epidemics in human history, occurred in the Ganges delta. Just like the previous two times, it quickly found its way through Iran and Iraq and into Southern Russia and Europe. The continent was still reeling from the previous epidemics that lasted from 1829 to 1851 when a fresh wave of illness struck. This time it meant business, and the Third Cholera Pandemics is considered to be the deadliest among the seven that laid waste to the world in the 19th and 20th century.

8. Hong Kong flu

Death toll: 2.5 million
Year: 1968 -1970

We are continuing our list of biggest epidemics in human history with the third influenza epidemics to strike the world in the 20th century again that originated in China. Soon, it spread to Hong Kong and from there all over the world. This time, it was influenza A subtype H3N2. It is believed that it was the strain that was created by a mutation of the H2N2 virus, the one that was responsible for the Asian Flu epidemics just 11 years earlier. Its severity varied from region to region. In Japan, it was rather mild compared to the United States where it caused 33,800 deaths.

7. Antonine Plague

Death toll: 5 million
Year: 165–180 AD

In 165 AD, Roman legions were laying siege to Seleucia. While there, they contracted a mysterious disease that was quick to spread throughout garrisons in Roman Empire. The illness was merciless, and about 25 percent of those who contracted it died. It ravaged throughout Rome, killing about 5 million people in the empire. During its height, some 2,000 people perished daily in Rome itself. The Greek physician Galen left a thorough account of the epidemics and modern scientists assume, based on his descriptions of the symptoms, that the disease in question was smallpox.

6. Smallpox epidemics 1520 in Mexico

Death toll 6.5 million (estimated 5 to 8 million)
Year: 1520 – 1521

Hernan Cortes landed in Mexico in 1519 on the Yucatan peninsula. He quickly proceeded to conquer the entire Aztec empire in about two years. While pillaging, raping and killing, Cortes and his men managed to do something even more sinister to the Aztecs, albeit unintentionally. They gave them smallpox. The virus, unleashed on a virgin soil, wreaked havoc among Aztecs, who lack any immune response to the disease. Between 5 and 8 million of them died in the first smallpox epidemics in the New World. But that wasn’t the worst thing that would happen to them in the 16th Century.

5. The Cocoliztli epidemic

Death toll: 17 million
Year: 1545 – 1576

25 years after the devastating smallpox epidemics, native population in Mexico suffered even worse disaster. The Cocoliztli virus was the name of a hanta-like virus that decimated the population of Yucatan Peninsula and Mexico in the 16th century. Deadly hemorrhagic fever was most likely caused by severe droughts that affected the region, causing a major shift of rats’ population in search for food and water, from which the virus jumped to humans. In two different occurrences, in 1545 and 1576, Cocolitzli virus almost wiped out the native population of Mexico. No wonder it’s on our list of biggest epidemics in human history.

4. HIV/AIDS

Death toll: 35 million (estimated 29.6 – 40.8 million)
Years: 1981 – present

The first known case and most probable origin point of HIV was Kinshasa in 1920. The then capital of Belgian Kongo and an important railroad crossroad, the city saw over million people passing through annually, which helped the virus spread all over Africa. But it wasn’t until the early 1980s that the disease became known in the west after more and more cases were discovered in the United States. The epidemic officially started on June 5th, 1981. Since then, between 29.6 million and 40.8 million people have died from HIV-related illness. At the end of 1015, about 36.7 million people have been living with HIV.

3. The Plague of Justinian

Death toll: 37.5 million (estimated 25 – 50 million)
Year: 541 – 542

The next in line on our list of biggest epidemics in human history is The Plague of Justinian that was the first bubonic plague epidemic in Europe. The disease was probably brought to Constantinople by grain ships from Egypt, carrying infected rats. The epidemics devastated the mighty Justinian Empire and stopped his efforts towards the recreation of the Roman Empire. Even the Emperor himself caught the plague but managed to survive it, unlike many of his fellow countrymen. It spread throughout the Mediterranean, as well as through Justinian’s rivals land in Sassanid Empire.

2. Spanish flu

Death toll: 75 million (estimated 50 -100 million)
Year: 1918 – 1919

In 1918, the world breathed a collective sigh of relief as the Great War, the biggest and bloodiest conflict in human history, ended. People everywhere started painstakingly putting their lives together after more than four years of misery, destruction, and death. Nobody suspected that even greater disaster was already set in motion. In March of 1918, a mess cook named Private Albert Gitchell died of influenza at Camp Funston in Kansas, one of many training camps set up by the United States Army preparing troops for overseas deployment to France. The origin of the virus is still contested, but Camp Funston was the site of the first recorded outbreak of 1918 flu epidemics that ravaged the world. According to the recent studies, between 50 and 100 million people died in 1918 and 1919. The disease was nicknamed the Spanish Flu because only Spain, among all other affected countries, didn’t downplay the number of casualties in daily newspaper reports and at the time, it seemed that the center of pandemics was there.

1. Black Death

Death toll: 137 million (estimated 75 to 200 million)
Year: 1346–1353

Regardless of which death toll estimate you take into account, the Black Death remains one of the biggest epidemics in human history. Some experts claim 75 million, the others as much as 200 million dead in both Europe and Asia. When it finally subsided, Europe was in ruins. Between 40 and 60 percent of the entire population was dead. Entire villages and towns were completely emptied of their inhabitants. Large swaths of cultivated land were reclaimed by nature. The entire economic and political situation on the continent was uprooted and some of the consequences are still felt today, as the shortage of labor spurred technical innovations that reduced the need for it.