February 3, 2020History of Medicine
There have been a number of significant pandemics recorded in human history, generally zoonoses which 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, 430 to 426 BCE
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.
Antonine Plague, 165 to 180 CE
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 CE), which may have been the same disease, 5,000 people a day were said to be dying in Rome.
Plague of Justinian, 541 to 750
This 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 CE and 700 CE.
Black Death, 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. This represented 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 1665-1666 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, 1918 to 1920
This flu 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.
Smallpox, Measles, Whooping Cough and Influenza
Encounters between European explorers and populations in the rest of the world often introduced local epidemics of extraordinary virulence. Disease killed part of the native population of the Canary Islands in the 16th century (Guanches), and half the native population of Hispaniola in 1518 was killed by smallpox. Smallpox also ravaged Mexico in the 1520s, killing 150,000 in Tenochtitlan alone, including the emperor. It also entered Peru in the 1530s, aiding the European conquerors. Measles killed a further two million Mexican natives in the 17th century. In 1618-1619, smallpox wiped out 90% of the Massachusetts Bay Native Americans. During the 1770s, smallpox killed at least 30% of the Pacific Northwest Native Americans. Smallpox epidemics in 1780-1782 and 1837-1838 brought devastation and drastic depopulation among the Plains Indians. Some believe that the death of up to 95% of the Native American population of the New World was caused by Old World diseases such as smallpox, measles, and influenza. Over the centuries, the Europeans had developed high degrees of immunity to these diseases, while the indigenous peoples had no such immunity. Smallpox devastated the native population of Australia, killing around 50% of Indigenous Australians in the early years of British colonization. It also killed many New Zealand Maori. As late as 1848-49, as many as 40,000 out of 150,000 Hawaiians are estimated to have died of measles, whooping cough and influenza. Introduced diseases, notably smallpox, nearly wiped out the native population of Easter Island. In 1875, measles killed over 40,000 Fijians, approximately one-third of the population. Measles also devastated the Andamanese Island population, where the Ainu population decreased drastically in the 19th century, due in large part to infectious diseases brought by Japanese settlers.
Syphilis was carried from the New World to Europe after Columbus' voyages. The findings suggest that Europeans could have carried the nonvenereal tropical bacteria home, where the organisms may have mutated into a more deadly form in the different conditions of Europe. The disease was more frequently fatal than it is today. Syphilis was a major killer in Europe during the Renaissance.
The Balmis Expedition (1803-1806) was a three-year mission to Spanish America and Asia led by Dr. Francisco Javier de Balmis with the aim of vaccinating millions against smallpox. Vaccination, a much safer way to prevent smallpox than older methods such as inoculation, had been introduced by the English physician Edward Jenner in 1798. By 1832, the federal government of the United States established a smallpox vaccination program for Native Americans.