Infectious diseases have been around since the beginning of human civilizations. People living in close proximity to each other and animals, poor sanitation and nutrition, overseas trading, and other factors have helped such diseases flourish, creating global pandemic.
According to information obtained from the History website, this is how six of the world’s worst pandemics finally ended.
Plague of Justinian
A single bacterium, Yersinia pestis, a fatal infection otherwise known as the plague, is responsible for causing three of the deadliest pandemics in recorded history.
The first of these plague pandemics, the Plague of Justinian, arrived in Constantinople, the capital of the Byzantine Empire, in 541 AD. Emperor Justinian had recently conquered Egypt, and received tribute from them in the form of grain, which was festered with fleas containing the disease.
The plague devastated Constantinople and spread quickly across Europe, Asia, North Africa and Arabia killing an estimated 30 to 50 million people, perhaps half of the world’s population.
“People had no real understanding of how to fight it other than trying to avoid sick people,” says Thomas Mockaitis, a history professor at DePaul University. “As to how the plague ended, the best guess is that the majority of people in a pandemic somehow survive, and those who survive have immunity.”
Black Death
The plague never really went away completely. The Black Death, which started in Europe in 1347, claimed a shocking 200 million lives in just four years.
People still had no scientific understanding of contagion, but they knew that it had something to do with proximity, says Mockaitis. That is why progressive officials in Venetian-controlled port city of Ragusa decided to keep newly arrived sailors in isolation until they could prove they were not sick.
The sailors were initially held on their ships for 30 days, but that was later increased to 40, or a quarantino, the origin of the word quarantine.
The Great Plague of London
After the Black Death, the plague resurfaced in London roughly every 20 years from 1348 to 1665, killing off 20 percent of the population living in the British capital each time.
By the early 1500s, England imposed the first laws to separate and isolate the sick. Homes stricken by plague were marked with a bale of hay strung to a pole outside. People with infected family members had to carry a white pole when they went out in public. Stray animals were believed to carry the disease, so there was a wholesale massacre of hundreds of thousands of them.
The Great Plague of 1665 was the last plague outbreak, killing 100,000 Londoners in just seven months. All public entertainment was banned and victims were confined their homes to prevent the spread of the disease. Red crosses were painted on their doors along with a plea for forgiveness: “Lord have mercy upon us.”
Although it might seem cruel to shut up the sick in their homes and bury the dead in mass graves, it may have been the only way to bring the last great plague outbreak to an end.
Smallpox
Smallpox was prevalent in Europe, Asia and Arabia for centuries, killing three out of ten people it infected. But the damage it caused in the old world paled in comparison to the sheer devastation it brought on native populations in the New World when the smallpox virus arrived in the 15th century with the first European explorers.
The indigenous peoples of modern-day Mexico and the United States had zero natural immunity to smallpox and the virus cut them down by the tens of millions.
“There hasn’t been a kill off in human history to match what happened in the Americas—90 to 95 percent of the indigenous population wiped out over a century,” says Mockaitis. “Mexico goes from 11 million people pre-conquest to one million.”
Smallpox eventually became the first virus epidemic to be ended by a vaccine. In the late 18th-century, a British doctor named Edward Jenner discovered that milkmaids infected with a milder virus called cowpox seemed immune to smallpox. Jenner famously injected his gardener’s 9-year-old son with cowpox and then exposed him to the smallpox virus with no ill effect.
In 1980 the World Health Organization announced that smallpox had been completely eradicated from the face of the Earth.
Cholera
Cholera hit England in the early- to mid-19th century, killing tens of thousands. Although the prevailing scientific theory of the day said that the disease was spread by foul air known as a “miasma,” a British doctor named John Snow suspected that the mysterious disease, which killed its victims within days of the first symptoms, lurked in London’s drinking water.
Following a series of investigations, Snow found a cluster of 500 fatal infections surrounding the Broad Street pump, a popular city well for drinking water.
With great persistence, he convinced local officials to remove the pump handle on the Broad Street drinking well, rendering it unusable, and like magic the infections dried up. Although Snow’s work did not cure cholera overnight, it eventually led to a global effort to improve urban sanitation and protect drinking water from contamination.
While cholera has largely been eradicated in developed countries, it is still a persistent killer in third-world countries lacking adequate sewage treatment and access to clean drinking water.
Spanish Flu
The Spanish Flu, first observed in Europe, the United States, and parts of Asia in 1918, spread swiftly around the world, resulting in 50 million deaths.
At the time, there were no effective drugs or vaccines to treat this killer flu strain. Hundreds of thousands of Americans died and body storage scarcity hit crisis level.
But the flu threat disappeared in the summer of 1919 when most of the infected had either developed immunities or died.
