See also: List of epidemics, Columbian Exchange, and Globalization and disease
There have been a number of significant epidemics and pandemics recorded in human history, generally zoonoses that came about with the domestication of animals, such as influenza and tuberculosis. There have been a number of particularly significant epidemics that deserve mention above the “mere” destruction of cities:
Plague of Athens, from 430 to 426 BC. During the Peloponnesian War, typhoid fever killed a quarter of the Athenian troops, and a quarter of the population over four years. 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.
Contemporary engraving of Marseille during the Great Plague of Marseille in 1720–1721
Antonine Plague, from 165 to 180 AD. Possibly smallpox brought to the Italian peninsula by soldiers returning from the Near East; it killed a quarter of those infected, and up to five million in all. At the height of a second outbreak, the Plague of Cyprian (251–266), which may have been the same disease, 5,000 people a day were said to be dying in Rome.
Plague of Justinian, from 541 to 750, was the first recorded outbreak of the bubonic plague. It 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 a half of the human population that it struck throughout the known world. It caused Europe’s population to drop by around 50% between 550 AD and 700 AD.
Black Death, from 1331 to 1353. The total number of deaths worldwide is estimated at 75 million people. Eight hundred years after the last outbreak, the plague returned to Europe. Starting in Asia, the disease reached 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 in 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. The disease killed approximately 100,000 people, 20% of London’s population.
The third plague pandemic started in China in 1855, and spread to India, where 10 million people died. During this pandemic, the United States saw its first outbreak: the San Francisco plague of 1900–1904. Today, isolated cases of plague are still found in the western United States.
Spanish flu, from 1918 to 1920. It infected 500 million people around the world, including people on remote Pacific islands and in the Arctic, and resulted in the deaths of 50 to 100 million people. Most influenza outbreaks disproportionately kill the very young and the very old, with higher survival rate for those in between, but the Spanish flu had an unusually high mortality rate for young adults. Spanish flu killed more people than World War I did and 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; the susceptibility of soldiers to Spanish flu might have been increased due to stress, malnourishment and chemical attacks. Improved transportation systems made it easier for soldiers, sailors, and civilian travelers to spread the disease.
Aztecs dying of smallpox, Florentine Codex (compiled 1540–1585)