Analyzing data from the World Health Organization (WHO), world meters, relevant posts available online and global history available online. I list the top ten deadliest pandemics.



Death toll: 1 million

Period: 1852-1860

Diseases: Cholera

Cholera is a bacterial infection that is mainly contracted through food and water. the third major outbreak of Cholera in the 19th century lasted from 1852 to 1860, Considered the most deadly in all seven cholera pandemics. The Third Cholera Pandemic originated in India, spreading from the Ganges River Delta before tearing through Asia, Europe, North America, and Africa and killed over one million people's lives. British physician John Snow had to get Success in tracking cases of cholera and eventually succeeded in identifying polluted water as the means of transmission for the disease.


Death toll: 2-4 million

Period: 1956-1958

Diseases: Influenza

Asian Flu was a pandemic outbreak of 'Influenza A Virus subtype H2N2', that originated in China in 1956 and lasted until 1958. It originated from a mutation in wild ducks combining with a pre-existing human strain. The virus was first identified in Guizhou. In these two years, Asian Flu traveled from the Chinese province of Guizhou to Singapore, Hong Kong, and the United States. A vaccine for H2N2 was introduced in 1957, and the pandemic slowed down.


Death toll: 5-10 million

Period: 165-180 AD

Diseases: Unknown

The Antonine plague which is also known as the Plague of Galen, this Plague was an ancient pandemic that affected Asia Minor, Egypt, Greece, and Italy and is thought to have been either Smallpox or Measles, but the main cause is still unknown. This unknown disease was brought back to Rome by soldiers returning from Mesopotamia around 165AD and spread a disease that would end up killing over 5 million people and destroyed the Roman army. This epidemic may have claimed the life of a Roman emperor, Lucius Verus, who died in 169 C.E and was the co-regent of Marcus Aurelius Antoninus. Ancient sources agreed that the epidemic appeared first during the Roman siege of Seleucia in the winter of 165–166.


Death toll: 10-12 million

Period: 1885-1860

Diseases: Bubonic plague

The Third Plague Pandemic, also referred to as the Modern Plague, refers to a bubonic plague pandemic that started in the Yunnan province in China, in 1855 during the fifth year of the Xianfeng Emperor of the Qing dynasty. It caused almost 12 million deaths. In the next 20 years it spread to Hong Kong and port cities around the world by rats that carried the infectious fleas responsible for the disease. Due to trading and shipping, it spread to many regions around the world. It even reached the U.S. from a plague-infected ship in Hawaii.


Death toll: 12-15 million

Period: 1545-1548

Diseases: Salmonella enterica

The cocoliztli epidemic or the great pestilence is a term given to millions of deaths in the territory of New Spain in present-day Mexico in the 16th century attributed to one or more illnesses collectively called cocoliztli. Cocoliztli was a swift and highly lethal disease. This mysterious illness characterized by high fevers and bleeding. Cocolitzli refers to a collection of pests. The symptoms were very much the same as Ebola but included a dark tongue, jaundice and neck nodules. It ravaged the Mexican highlands in epidemic proportions. The disease became known as Cocoliztli by the native Aztecs, and had devastating effects on the area’s demography, particularly for the indigenous people. Based on the death toll, this outbreak is often referred to as the worst disease epidemic in the history of Mexico.


Death toll: 25-35 million

Period: 2005-2012

Diseases: HIV/AIDS

Human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV). It was first identified in the Democratic Republic of the Congo in 1976, HIV/AIDS has truly proven itself as a global pandemic. HIV is spread primarily by unprotected sex, contaminated blood transfusions, hypodermic needles, and from mother to child during pregnancy, delivery, or breastfeeding. Currently, between 31 and 35 million people are living with HIV, the vast majority of those are in Sub-Saharan Africa. As awareness has grown, new treatments have been developed that make HIV far more manageable, and many of those infected go on to lead productive lives.


Death toll: 35-50 million

Period: 541-542 AD

Diseases: Plague

This deadly pandemic affected the Eastern Roman Empire, specifically Constantinople and port cities along the Mediterranean sea. Some historians believe the plague of Justinian was one of the deadliest pandemics in history, resulting in the deaths of an estimated 25–100 million people during two centuries of recurrence, a death toll equivalent to as much as half of Europe's population at the time of the first outbreak. The Justinian Plague left its mark on the world, killing up to an estimated 5,000 people per day and eventually resulting in the deaths of 40 percent of the city of Constantinople. Necrosis of the limbs was one of the terrifying symptoms.


Death toll: 50-100 million

Period: 1918-1920

Diseases: Influenza

The Spanish flu (also known as the 1918 flu pandemic) was an unusually deadly influenza pandemic. Lasting from January 1918 to December 1920, it infected 500 million people and the death toll is estimated to have been anywhere from 50 million and possibly as high as 100 million, making it one of the deadliest pandemics in human history. This disease killed more people than WWI. Most influenza outbreaks had always previously killed only juveniles and the elderly or weakened patients; it had begun striking down hardy and completely healthy young adults while leaving children and those with weaker immune systems still alive. Scientists offer several possible explanations for the high mortality rate of the 1918 influenza pandemic. Some analyses have shown the virus to be particularly deadly because it triggers a cytokine storm, which ravages the stronger immune system of young adults.


Death toll: 75-200 million

Period: 1331-1353

Diseases: Plague

The Black Death, also known as the Pestilence, the Great Bubonic Plague, the Great Plague or the Plague, or less commonly the Great Mortality or the Black Plague, was the most devastating pandemic recorded in human history, resulting in the deaths of an estimated 75 to 200 million people in Eurasia, peaking in Europe from 1347 to 1351. Starting in 1331, it is estimated to have claimed 30-60% of the population of Europe. Thought to have originated in Asia, the Plague most likely jumped continents via the fleas living on the rats that so frequently lived aboard merchant ships. Ports being major urban centers at the time, were the perfect breeding ground for the rats and fleas, and thus the insidious bacterium flourished, devastating three continents in its wake. This plague was the origin of the word quarantine and the start of its practice in the Western world. The plague may have reduced the world population from an estimated 475 million to 350–375 million in the 14th century. It took 200 years for Europe's population to recover to its previous level, and some regions (such as Florence) only recovered by the 19th century. Outbreaks of the plague recurred until the early 20th century.


Death toll: 300-500 million

Period: 3rd BC- 20th century

Diseases: Smallpox

The origin of smallpox is unknown. Smallpox is thought to date back to the Egyptian Empire around the third century BCE based on a smallpox-like rash found on three mummies. Smallpox was an infectious disease caused by one of two virus variants, Variola major and Variola minor. The term "smallpox" was first used in Britain in the early 16th century to distinguish the disease from syphilis, which was then known as the "great pox". Smallpox was a devastating disease. On average, 3 out of every 10 people who got it died. The initial symptoms of the disease included fever and vomiting. This was followed by the formation of sores in the mouth and a skin rash. Over several days the skin rash turned into characteristic fluid-filled bumps with a dent in the center. The bumps then scabbed over and fell off, leaving scars. The disease was spread between people or via contaminated objects. Prevention was by the smallpox vaccine. Once the disease had developed, certain antiviral medication may have helped. Those who survived had extensive scarring of their skin, and some were left blind.

In 18th-century Europe, it is estimated 400,000 people per year died from the disease, and one-third of the cases resulted in blindness. These deaths included four reigning monarchs and a queen consort. Smallpox is estimated to have killed up to 300 million people in the 20th century and around 500 million people in the last 100 years of its existence. As recently as 1967, 15 million cases occurred a year.

In 1959, the World Health Organization (WHO) initiated a plan to rid the world of smallpox. Unfortunately, this global eradication campaign suffered from a lack of funds, personnel, and commitment from countries, as well as a shortage of vaccine donations. Despite their best efforts, smallpox was still widespread in 1966, causing regular outbreaks in multiple countries across South America, Africa, and Asia.