Disease epidemics and Pandemics have been
some of the greatest historical threats to humanity through the ages. When people reel off numbers and statistics
about the great plagues of the past, it can be easy to lose perspective on just how horrific
these national and international tragedies have been. Today, we’re going to take a look at ten
of history’s most nightmarish epidemics and pandemics, and tell you exactly how devastating
each one has been. Number 10. Yellow Fever – 1694 to 1878
While it may have been a while since you’ve even heard about Yellow Fever, from the 1600s
to the early 1900s it was one of the most feared diseases on the planet – though scientists
estimate the disease is possibly over three-thousand years old. It’s described by the World Health Organization
as an acute viral haemorrhagic disease transmitted via mosquito bites. The key symptoms of the disease are headache,
fever, nausea, vomiting, fatigue, muscle pain, and jaundice, which gives the disease its
name due to the slightly yellow tint it often gives to the skin of sufferers. And Yellow Fever is not to be messed with:
Those who develop severe symptoms often die within a week to ten days. Yellow Fever has spread like wildfire in mosquito
filled tropical areas like the Caribbean and numerous countries in the Americas, including
the United States. The Yellow Fever Epidemics of 1694 to 1855,
which ravaged Boston, Philadelphia, and Norfolk, Virginia, were brutal, but the 1878 outbreaks
in Mississippi River Valley were the worst of all. Over the Spring and Summer of that year, around
120,000 people were infected with Yellow Fever, and from thirteen-thousand to twenty-thousand
of those infected individuals died from the disease. Because its infection vector is mosquitos,
the disease can spread incredibly quickly from just one infected person to a whole community
in a hot or tropical environment. Thankfully, scientists have since developed
an extremely effective vaccine against the disease that is generally both affordable
and easy to access. However, this hasn’t stopped cases from
popping up sporadically in Africa, Asia, and South America. Number 9. Japanese Smallpox Epidemic – 735 – 737
Things really take a turn for the worst with the horrific Japanese smallpox epidemic of
the 700s. This won’t even be the last time we encounter
Smallpox on this list, and that’s because it’s an extremely infectious and dangerous
disease. Caused by the Variola Major Virus, Smallpox
causes fever, vomiting, and infectious sores and scabbing across the body that can spread
the virus through contact. It can also cause oozing pustules on the tongue
and in the throat, which makes the virus spreadable through droplets in the air released by coughing. The fatality rate for Smallpox at its worst
was as high as a terrifying 30%. As an example of this truly scary mortality
rate in action, we turn to Japan in the 8th century. Starting in the Northern Kyushu region in
735, by the time the viral outbreak reached its peak in 737, it’s believed to have killed
up to one million people. The prevalence and deadliness of Smallpox
outbreaks in Japan even made a lasting cultural scar on Japanese folklore, with the belief
that the disease was caused by a demonic entity – because something this awful surely had
to be supernatural in nature. Number 8. Hong Kong Flu – 1968 – 1970
Back to an old favorite you’re also likely to see a lot more of on this list: The Flu. Specifically, the H3N2 strain, aka the Hong
Kong Flu, the third influenza pandemic to occur in the 20th Century. Part of the reason you so often see flus and
variations of the flu in major global pandemics is that it’s one of the more hardy and adaptable
viruses out there. Many strains of flu – the Hong Kong Flu
included – undergo a process known as antigenic drift. Quick biology lesson: It’s hard to fall
victim to the same strain of a virus twice, because the body’s immune system can recognise
the virus and create the proper antibodies to fight it. When a virus undergoes antigenic shift, though,
it’s essentially like wearing a disguise that allows it to mount a sneak attack on
the body. Before your immune system knows what hit it,
you’re in deep trouble. That was definitely the case for the victims
of the Hong Kong Flu, which is believed to have mutated from an earlier strain from 1957. The disease is estimated to have killed between
one and four million people worldwide in its two years of major activity, most of which
were people over sixty. Number 7. The Antonine Plague – 165 – 180
Next, an ancient plague so brutal it’s said to have aided in the collapse of the legendary
Roman Empire. Also known as the Plague of Galen, named after
the Greek physician who first identified it, this mysterious disease is thought to have
been brought back into Roman Empire by Legionaries who’d done tours in East Asia. The disease first manifested in Asia Minor,
before spreading to Greece, and then eventually to Italy itself, where it spread like wildfire
in the densely-populated cosmopolitan cities like Rome, killing as many as two-thousand
people a day at the height of its devastation. Nobody could even really understand the plague,
let alone fight it. It’s believed that the disease even killed
two of the Empire’s rulers: Lucius Verus and Marcus Aurelius. The final death toll is believed to have been
seven-to-ten-percent of the Roman Empire, though some estimate it as high as fifteen
percent, as it spread into other European countries like Spain and further into Egypt
and South Africa. And what was this mystery disease believed
to be? Based on accounts of symptoms at the time,
scholars believe it was most likely an outbreak of Smallpox. See? We told you it would come back. Number 6. The Third Plague – 1855
The Third Plague was a record breaker in a number of terrible categories. It not only straddled an over one hundred-year
period, from 1855 to 1959, it was also the first case of bubonic plague to strike all
five major continents – with major outbreaks in Hong Kong in 1894, Bombay in 1896, Sydney
in 1900, Cape Town in 1901, and Los Angeles in 1924. It also caused around twelve million deaths
during its reign of terror, devastating populations worldwide, and it inspired containment measures
unlike anything the world had ever seen before, to varying degrees of success. Having gained knowledge of the virus’ transmission
through fleas and rats, as well as its early warning signs and symptoms, the infected areas
mounted a hardcore defense against the invading disease. Towards the end of the 19th century, doctors
were experimenting with “plague serums” that often killed as many people as they cured. Other methods used involved vast quarantines
and controlled rodent burns meant to contain the spread. Ultimately, a lot of these methods weren’t
much use, but it did set precedents in terms of the scale of global reaction to a major
viral pandemic. Number 5. HIV/AIDS – 1981 – Present
One of the most well-known sexually transmitted diseases of all time is the Human Immuno-Deficiency
Virus – and the Acquired Immune Deficiency Syndrome that sometimes results from it if
untreated. More commonly known as HIV and AIDS. The disease spreads through bodily fluids
in sexual contact, or through the sharing of needles or botched blood transfusions. The real danger of the disease is that it
remains virtually symptomless for an extremely long period of time compared to many diseases,
allowing it to infect huge numbers of people during this period. If left untreated, the disease can lead to
infected people becoming devastatingly immunocompromised, often leading to death from another infection
that the body can no longer fight off. The modern HIV/AIDS epidemic first became
known in 1981, and has continued through to today. There are currently around 37.7 million people
living with HIV/AIDS today, and since its discovery, the disease has killed over twenty-five-million
people. What makes the HIV/AIDS epidemic particularly
egregious is the poor government response to containing the outbreak and properly treating
those infected. The attitude towards the virus was exemplified
by the advice Washington gave the Center for Disease Control in approaching the outbreak,
with the gist of their guidance being to “Look pretty and do as little as possible.” As a result, millions of the deaths that resulted
from HIV/AIDS were likely extremely preventable if the proper treatment had been given. Many of the people infected with HIV/AIDS
– especially during the early years – were gay, African-American, poor, and drug-users. This is often stated as the main reason for
the lax governmental response to the disease. Thankfully, in the last few decades, research
into HIV/AIDS has pioneered treatments that give sufferers long and fulfilling lives in
spite of their illness. Number 4. Plague of Justinian – 541 – 542
Now, on to a plague of truly mythic proportions. In more recent years, the sheer extent of
the effect of the Plague of Justinian has been cast into doubt, but many historical
accounts of this plague place its death toll between twenty-five and fifty-million – around
ten percent of the world population at the time. Much like the more recent Third Plague we
mentioned earlier, this was likely another case of the extremely dangerous bubonic plague
spread by rats and their fleas across the Byzantine Empire in the 6th Century. The Plague of Justinian likely originated
in Asia, but infected rats were inadvertently brought into African nations like Egypt through
Roman trade routes. Like almost all major outbreaks of the bubonic
plague, cases spread like wildfire across the cosmopolitan empire, bringing death and
destruction wherever it went. After hearing enough of these accounts, you
begin to really understand the sentiment behind the old cliché “avoid it like the plague.” Number 3. Spanish Flu – 1918 – 1919
These final three are the deadliest pathogenic outbreaks in the history of mankind, starting
with history’s most dangerous case of Influenza: The Spanish Flu of 1918, which devastated
a Post-World-War-One world with a confirmed forty-to-fifty-million deaths across the globe. The disease is believed to have originated
in military personnel returning from the battlegrounds of the war and introducing the disease back
into civilian populations, where it went on to infect a third of the global population. While like many flus, this disease was particularly
deadly to the young and elderly, what made the Spanish Flu even more horrifying was the
fact it also had an extremely high mortality rate of healthy young people aged around twenty-five. The lack of effective flu vaccines at the
time allowed the Spanish Flu to sweep across the globe like the grim reaper, claiming the
lives of tens of millions. Number 2. Smallpox – 1520
And we return to a Smallpox one last time, for the only incidence in recorded history
where a virus was complicit in a man-made genocide multiple times. Until its eventual eradication through treatment
and the development of vaccines, Smallpox was one of the greatest threats to human life. In Europe in the 1800s, it’s believed that
the virus killed almost half a million people every year. In the late 1700s, it’s believed Native
Americans were murdered by being tricked into accepting Smallpox-infected blankets by the
British and Americans, accounting for almost 90% of indigenous people killed at the time. But this specific example, occurring in the
year 1520, shows that Smallpox being brought into South America by Spanish Conquistadors
may have been the final nail in the coffin of the Aztecs. After being introduced into the Aztec coastal
territories by the Spanish in the mid-to-late 1510s, the disease spread inwards, until it
reached the Aztec capital of Tenochtitlan in 1520. A year and fifty-six-million-deaths later,
the Aztec civilisation fell, leaving the territory that would later become modern Mexico up for
grabs. And you better believe the Conquistadors grabbed
it, stepping over millions of Aztec bodies to do so. Today the disease is making a global comeback
tour, thanks to overprivileged first world soccer moms who don’t believe in vaccines. And finally Number 1. The Bubonic Plague, aka The Black Death – 1347
– 1351 We’ve saved the very worst for last. When it comes to The Black Death of the 14th
Century, the lucky ones died quickly. The unlucky ones lived long enough to see
society collapse around them, as their body erupted in the large, oozing buboes that gave
the disease its name before the unbearable sickness and pain brought them to their end. The Black Death killed a third, and by some
estimates, almost half, of Europe’s population. In the four-year period this disease was most
active, after being carried into mainland Europe by stowaway rats with their own infected
stowaway fleas on trading ships, it killed over two-hundred-million people. The devastation of the Black Death was so
horrific that it took the continent over two-hundred years to return to its pre-plague population,
and left its mark as one of history’s greatest catastrophes – killing roughly twice the
number of people as World War One and Two combined! So, remember, folks: Wash your hands and don’t
kiss any rats you find on random ships. Thanks for watching this episode of The Infographics
Show! If you’re doing the right thing and staying
indoors, don’t worry about getting bored, we’ve got plenty more viral videos to keep
you entertained. Why not check out “Diseases That Will Kill
You The Quickest” and “Scientists Wake Up Ancient Viruses Unknown to Man.” Stay safe, and stay healthy!
