page_title: Pandemic
section_title: Notable outbreaks
hierarchical_section_title: Pandemic / Notable outbreaks
caption_attribution_description: Français&#160;: Scène de la peste de 1720 à la Tourette (Marseille)
context_page_description: A pandemic is an epidemic of an infectious disease that has spread across a large region, for instance multiple continents or worldwide, affecting a substantial number of people. A widespread endemic disease with a stable number of infected people is not a pandemic. Widespread endemic diseases with a stable number of infected people such as recurrences of seasonal influenza are generally excluded as they occur simultaneously in large regions of the globe rather than being spread worldwide.
  Throughout human history, there have been a number of pandemics of diseases such as smallpox and tuberculosis. The most fatal pandemic in recorded history was the Black Death, which killed an estimated 75–200 million people in the 14th century. The term was not used yet but was for later pandemics including the 1918 influenza pandemic. Current pandemics include COVID-19 and HIV/AIDS.
context_section_description: In human history, it is generally zoonoses such as influenza and tuberculosis which constitute most of the widespread outbreaks, resulting from the domestication of animals. There have been a number of particularly significant epidemics that deserve mention above the "mere" destruction of cities:
  Plague of Athens (430 to 426 BC): During the Peloponnesian War, typhoid fever killed a quarter of the Athenian troops and a quarter of the population. This disease fatally weakened the dominance of Athens, but the sheer virulence of the disease prevented its wider spread; i.e. it killed off its hosts at a rate faster than they could spread it. The exact cause of the plague was unknown for many years. In January 2006, researchers from the University of Athens analyzed teeth recovered from a mass grave underneath the city and confirmed the presence of bacteria responsible for typhoid.
  Antonine Plague (165 to 180 AD): Possibly measles or smallpox brought to the Italian peninsula by soldiers returning from the Near East, it killed a quarter of those infected, up to five million in total.
  Plague of Cyprian (251–266 AD): A second outbreak of what may have been the same disease as the Antonine Plague killed (it was said) 5,000 people a day in Rome.
  Plague of Justinian (541 to 750 AD): The first recorded outbreak of bubonic plague started in Egypt and reached Constantinople the following spring, killing (according to the Byzantine chronicler Procopius) 10,000 a day at its height, and perhaps 40% of the city's inhabitants. The plague went on to eliminate a quarter to half the human population of the known world. It caused Europe's population to drop by around 50% between 550 AD and 700 AD.
  Black Death (1331 to 1353): The total number of deaths worldwide is estimated at 75 to 200 million. Eight hundred years after the last outbreak, the plague returned to Europe. Starting in Asia, the disease reached the Mediterranean and western Europe in 1348 (possibly from Italian merchants fleeing fighting in Crimea), and killed an estimated 20 to 30 million Europeans in six years; a third of the total population, and up to a half in the worst-affected urban areas. It was the first of a cycle of European plague epidemics that continued until the 18th century. There were more than 100 plague epidemics in Europe during this period. The disease recurred in England every two to five years from 1361 to 1480. By the 1370s, England's population was reduced by 50%. The Great Plague of London of 1665–66 was the last major outbreak of the plague in England and killed approximately 100,000 people, 20% of London's population.
  Third plague pandemic (1855): Starting in China, it spread into India, where 10 million people died. During this pandemic, the United States saw its first outbreak: the San Francisco plague of 1900–1904. Today, sporadic cases of plague still occur in the western United States.
  The 1918 flu pandemic infected half a billion people—around the world, including on remote Pacific islands and in the Arctic—killing 20 to 100 million. Most influenza outbreaks disproportionately kill the very young and the very old, with higher survival rates for those in between, but the 1918 pandemic had an unusually high mortality rate for young adults. (It killed more people in 25 weeks than AIDS did in its first 25 years.) Mass troop movements and close quarters during World War I caused it to spread and mutate faster, and the susceptibility of soldiers to the flu may have been increased by stress, malnourishment and chemical attacks. Improved transportation systems made it easier for soldiers, sailors and civilian travelers to spread the disease.
  Encounters between European explorers and populations in the rest of the world often introduced epidemics of extraordinary virulence. Disease killed part of the native population of the Canary Islands in the 16th century (Guanches). Half the native population of Hispaniola in 1518 was killed by smallpox. Smallpox also ravaged Mexico in the 1520s, killing 150,000 in Tenochtitlán alone, including the emperor, and in Peru 
caption: Contemporary engraving of Marseille during the Great Plague of Marseille, 1720–1721
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