Epidemics and pandemics are two of the worst tragedies in the history of humankind, killing millions and transforming whole civilizations. Though medicine and epidemiology have made great strides in being able to prevent and treat such outbreaks, history still reads like a book of horror with ruinous loss and tremendous social upheaval. From the broad impact of contemporary pandemics to those that hit ancient civilizations, every outbreak has imprinted its signature on history. This timeline emphasises the world's worst pandemics and epidemics, from the most recent to the oldest, highlighting their devastating effects and the advances made in avoiding future catastrophes.

List of the deadliest epidemics and pandemics in history

Most lethal global health crises

COVID-19 pandemic (2019-Present)

The pandemic due to the new coronavirus SARS-CoV-2 started in December 2019 and up to now. The pandemic increased very fast, infected hundreds of millions, and killed more than 6.4 million people up to mid-2022. The pandemic disturbed normal life, created epidemic disease, and overwhelmed the world's healthcare system. Vaccines and drugs reduced its impact everywhere but COVID-19 is still a public health issue.

Zika virus epidemic (2015-Present)

The Zika virus epidemic, which started in 2015, decimated South America, Central America, and a portion of the United States. Zika virus is transmitted and disseminated by the mosquito, leading to flu-like illness in adults but microcephaly as a congenital defect in infants born to affected mothers. Population control of mosquitoes has been one of the foundations of measures in preventing further spread.

West African Ebola epidemic (2014-2016)

In 2014-2016, Ebola struck West Africa and resulted in more than 28,000 cases with 11,325 fatalities. The pandemic mostly ravaged Guinea, Liberia, and Sierra Leone, but to a lesser extent was seen from Nigeria, Mali, Senegal, and other locations outside Africa. Though no exact cure has been discovered for Ebola, its treatment and vaccine production have greatly enhanced since this pandemic.

H1N1 Swine Flu pandemic (2009-2010)

H1N1 flu or Swine Flu broke out in Mexico during the spring of 2009 and spread across the globe quickly. It infected nearly 1.4 billion individuals within one year and resulted in the deaths of approximately 151,700 to 575,400 individuals. Young adults and children were attacked by the flu more often than the remaining parts of the flu viruses responsible for killing older people. The production of vaccinations at a relatively fast pace withheld the spread of the virus.

AIDS epidemic and pandemic (1981-Present)

Even though since its discovery in the early 1980s, HIV virus-inducing AIDS has already claimed over 35 million lives worldwide, AIDS has been cured by antiretroviral therapy (ART) and HIV-positive individuals have lived long and healthy years because they were once an international health emergency. The disease is still a large health problem even though it can be treated, especially in sub-Saharan Africa.

Asian Flu (1957-1958)

The Asian Flu epidemic, which spread from China, took more than 1 million lives worldwide. The H2N2 flu virus devastated Asia, Europe, and North America to wholesale illness and death. Young adults were viciously decimated by the flu, and response globally prompted record-breaking breakthrough in vaccine science and pandemic preparation.

Spanish Flu (1918-1920)

The 1918-1920 Spanish Flu pandemic was the deadliest to have struck, claiming an estimated 50 million and infecting about one-third of the global population. The illness spread quickly after World War I, driven by unhygienic war situations. Although the illness was named the Spanish Flu, the illness was not Spanish, but due to the fact that it was neutral and didn't have war censorship, it became associated with Spain. The flu was very lethal because it was not vaccine-backed and ineffective medicine couldn't stop it.

American polio epidemic (1916)

The 1916 US polio epidemic already claimed the lives of 27,000 victims and 6,000 deaths. Polio is common among children and only incapacitates and kills a handful. Following decades of sporadic epidemics, the arrival of the Salk vaccine in 1954 had drastically reduced polio cases. The United States officially declared itself polio-free in 1979, although the disease remains a public health issue in some parts of the world today.

Flu pandemic (1889-1890)

The 1889-1890 flu pandemic, Russian Flu, spread at full speed with new transport connections in the age of industry and reached the world within a few months. It caused approximately 1 million fatalities. In the absence of modern transport, the virus propagated on railway and sea links at maximum speed, particularly along transport corridors from Europe to Asia and North America. The rate of pandemic spread also indicated the vulnerability of the public health system of the time.

Philadelphia yellow fever epidemic (1793)
Yellow fever devastated the American capital, Philadelphia, in 1793. Mosquito-borne illness killed over 5,000, 10% of the population. Everyone was panicked and public health measures were delayed, with authorities believing that slaves were immune to it. Autumn weather and dead mosquitoes did not arrive until the end of the epidemic.

Russian Plague (1770-1772)

The Russian Moscow Plague of 1770-1772 was followed by riots, violence, and mass hysteria. The plague caused an estimated death toll of 100,000 and reduced public order in the Russian Empire to zero. Empress Catherine the Great herself was unable to restore normalcy after the devastation. The plague introduced mass political unrest into Russia.

Great Plague of Marseille (1720-1723)

The Great Marseille Plague started in 1720 when an eastern Mediterranean vessel had landed in France with plague-ridden fleas and rats on board. More than 100,000 people in Marseille and nearby settlements were killed by the disease over a period of three years. The disease spread swiftly as there were no draconian quarantine laws in place and thus there was a health epidemic of very serious proportions across south France.

Great Plague of London (1665-1666)

The London Great Plague, the final of the Black Death's plagues of great height in Britain, started in 1665. It murdered an estimated 100,000, or 15% of urban residents. It rapidly spread in the city's muck and poisonous air. The plague was ultimately ended by the Great Fire of London in 1666 that destroyed much of the city, including infected districts.

American Plagues (16th Century)

American Plagues were diseases that the Europeans brought with them to the Americas in the 16th century. Smallpox and measles and other foreign diseases killed among the people in the native tribes, leading to the fall of the Inca and Aztec empires. About 90% of the native population of the Americas were wiped out by the diseases and thus paved the way for Europe to be conquered.

Cocoliztli epidemic (1545-1548)

1545-1548 Cocoliztli plague which killed Mexico and Central America was estimated at 15 million individuals dead. Plague which appeared in the form of hemorrhagic fever infected the nation at lightning-fast speeds, killing weakened Native groups as a result of other plagues as well as due to drought already prevalent in those lands. One of the further causes for the collapse of the Aztec Empire.

Plague of Justinian (541-542 AD)

Plague of Justinian, where in the Byzantine Empire this happened under Emperor Justinian I, was due to the bacterium Yersinia pestis. The plague killed 25-50 million and up to 10% of the world's population. The plague undermined the power of the Byzantine Empire and established the cyclical plagues which devastated Europe for centuries.

Plague of Cyprian (250-271 AD)

The Plague of Cyprian, which is named for the bishop who chronicled the epidemic, killed thousands of people a day within the Roman Empire. The epidemic is estimated to have been one of viral hemorrhagic fever, and the contagiousness of the epidemic so rapidly caused the empire to be vulnerable to invasion. As many as 5,000 people per day were reported dead in Rome alone.

Antonine Plague (165-180 AD)

Antonine Plague, caused by smallpox, during the rule of Marcus Aurelius in the Roman Empire. It killed a total estimated number of about 5 million individuals, including soldiers returning from their campaigns in the East. It hastened the onset of the end of the Pax Romana and the ease with which the Roman Empire collapsed.

Plague of Athens (430 BC)

The Athenian Plague had occurred in the second year of the Athens-Sparta conflict during the time of the Peloponnesian War. The epidemic killed approximately 100,000 people, among them the Athenian statesman Pericles. Town overcrowding had caused the epidemic because all Athenians had found refuge behind the city walls. There is no etiology but typhoid fever is one of the best-known hypotheses of the epidemic.

Prehistoric epidemic (c. 3000 BC)

A find of a 5,000-year-old Chinese hut containing skeletons confirms an ancient epidemic. All the skeletons were found within one hut and must have been killed by a contagious disease. They were not segregated by age, and later the hut went up in flames, which indicated the scale of the disaster. The find confirms that epidemics have been happening among human beings for centuries.