In this video we’ll be exploring the impact
of one of the most significant epidemic diseases
to shape world history, and that is smallpox.
In the words of medical historian, Roy Porter,
epidemics arose with society and sickness
has been and will remain a social product
no less than the medicine which opposes it;
civilization brings not just discontents,
but diseases.
Paleolithic society, or society prior to the
advent of farming, saw very few epidemic diseases.
People lived in small groups and practiced
nomadic lifestyles in which they weren’t
in one place long enough to pollute the environment.
They had no domesticated animals, which are
themselves sources of epidemic diseases, and
they ate a relatively healthy diet.
But the advent of farming, the Neolithic Revolution,
changed all of that.
As farming brought civilization, and brought
with it permanent settlements, large social
groups, close contact with animals, and monoculture
diets, humans came into contact with new pathogens.
Some of those pathogens – like influenza
or tuberculosis – came from animals.
Others – like cholera or typhoid – came
from a contaminated water supply.
And still others – like malaria – came
from insect and vermin that infested human
civilizations and these pathogens and the
diseases they brought with them often affected
human civilizations that were nutritionally
deficient – whether because of food shortages
or because of reliance on monoculture had
resulted in vitamin or nutrient deficiencies.
So the pathogens that brought epidemic diseases
brought destruction into human societies,
and we’ve named a few, but there are hundreds
of others – measles; polio; hepatitis; diphtheria;
whooping cough; the list goes on and on.
But what we want to do today is to take a
look at one of the deadliest and most destructive
epidemic diseases in human history – smallpox.
The primary form of smallpox, that has affected
human civilizations, is caused by the variola
virus; its symptoms begin with flu-like symptoms
and then those flu-like symptoms give way
to a rash across the body; the rash results
in skin sores that fill with a thick, opaque
liquid that eventually form pustules; the
pustules form a crust and scab over, and then
within a few days those scabs fall off – typically
leaving scars.
Smallpox, throughout history, has been highly
lethal and highly contagious – killing about
thirty percent of the people it infected and
leaving others scarred, sterile, or if the
pox virus infected the eyes – blinded by
the effects of smallpox.
Less common strains, like hemorrhagic smallpox,
had a fatality rate much closer to a hundred
percent.
So it was an incredibly deadly and destructive
virus.
Smallpox was eradicated from the world in
1979, making it the first epidemic disease
completely eradicated in world history.
But before that, smallpox was responsible
for billions of deaths – estimates rest
at about three hundred to five hundred million
in just the 20th century, and smallpox dates
much further back than that.
So smallpox and the destruction wrought by
smallpox has defined human history in many
ways.
It’s believed that the disease originated
about ten thousand years ago in Africa, particularly
in eastern Africa, and then spread throughout
the ancient world.
A 2015 article from The Journal of Viruses
suggests that the variola virus emerged in
east Africa as a mutation of a closely-related
virus that evolved as the domesticated camel
emerged, as a new host.
This virus developed into repeated epidemics
within a few millennia, and ravaged human
civilizations, human populations, across the
globe.
There’s evidence of Egyptian mummies bearing
the scars of pox, descriptions of what appear
to be smallpox appear in medical treatises.
There are mentions in Chinese and Indian literature.
The mortality rate in these ancient civilizations,
and in future generations, was exceptionally
high so many societies developed the custom
of not naming infants until after they’d
survived the pox virus.
So smallpox spread from Africa into Asia,
and then from Asia into Europe; smallpox appeared
in large parts of Europe by the Middle Ages,
and there are contemporary accounts of the
disease decimating populations across Europe.
So the spread of smallpox is closely connected
to the movement of people across regions and
continents in world history, and that would
continue into the early modern period as well,
as the Europeans spread smallpox into the
Americas, where the devastation was even greater.
In the so-called Old World – Europe; Asia;
and Africa – the most common form of smallpox
killed perhaps thirty percent of its victims,
while blinding and disfiguring many others.
But the effects were even worse in the Americas,
where the indigenous populations had little
to no immunity to the disease.
They’d had no exposure to smallpox prior
to the arrival of the Europeans at the end
of the 15th century, and therefore had developed
no resistance to the disease, and so smallpox
ripped through Native American populations,
devastating the Inca; devastating the Aztecs.
Historians believe that smallpox and other
European diseases reduced the indigenous populations
of North and South America by as much as ninety
percent, making it a blow far greater than
any military defeat or any advantage from
military weaponry.
So it’s fair to say, as historian Jared
Diamond has, that disease was – if not THE
decisive factor, at the very least a crucial
determinate in Europeans’ dominance in the
modern era.
The ability of smallpox to weaken the native
populations opened them up to easy conquest
by the European colonists, and allowed Europe
to establish dominance over the Americas – and
that dominance and use of smallpox as a weapon
would continue.
In fact, there are suggestions that Lord Jeffery
Amherst – commander-in-chief of the British
forces in North America during the Seven Years
War, also known as the French and Indian War,
in North America – even advocated handing
out smallpox infected blankets to his Native
American foes in 1763.
So smallpox was not only at the center of
migrating populations, and at the center of
connections between civilizations, but was
defined and used by conflict by civilizations.
It would shape the nature of history, not
only in the ancient and medieval worlds, but
in the early modern and modern worlds as well.
Fortunately, it was the first epidemic disease
to be completely eradicated from the face
of the earth, in large part due to the long
incubation period of the disease, and in large
part due to experimentation with vaccines.
The concept of inoculation, and inoculation
more or less means exposing and individual
to small amounts of a disease in order to
create immunity, was well known in Africa;
India; and China by the 17th century; it gained
popularity in Europe by the 18th century.
Smallpox became one of the first targets of
inoculation, and the risky procedure proved
to be fairly successful – killing just a
small fraction of those it infected, and resulting
in much milder forms of the disease for those
who had been inoculated.
In Asia, the very first attempts at inoculation
against smallpox were a practice called variolation,
and variolation was the deliberate infection
of an individual with a very small dose of
the smallpox virus.
The belief was that exposure to this very
small amount of the pathogen would produce
immunity to the disease and render anyone
who got the disease later; it would give them
a much milder case of the disease.
So what they basically did was they took dried
smallpox scabs and crushed it up into a fine
powder, that powder was then inhaled through
the nostril of the person being inoculated,
and they fell prey to a very mild form of
the disease.
Once they recovered, they were mostly immune
to smallpox – between one and two percent
of the population of the inoculated population
died from smallpox, compared to thirty percent
of the population at large.
So by 1700, the concept of variolation had
spread from China into other parts of Asia;
Africa; the Ottoman Empire; and then into
Europe.
In 1796, a new discovery was made by a man
named Edward Jenner, a British doctor; he
noticed that women – in particular – who
had developed cowpox – and cowpox was a
related virus, closely related to smallpox
– but women who had developed cowpox were
largely resistant to the smallpox disease,
and so he noticed this among dairy-maid populations
and decided to experiment and see if his theory
was correct.
So what he did was he deliberately injected
a young boy with a small dose of cowpox to
see if it, too, would create immunity to smallpox,
and it was successful, leading to the establishment
of what medical historians call vaccination
because this boy did not get sick vaccination
became an important practice in the European
medical community.
Further testing proved conclusively that cowpox
virus was able to build immunity and that
became the go-to for smallpox vaccinations.
Through global efforts, smallpox was completely
eradicated by 1979, and is no longer a concern
within the world at large.
But the story of smallpox reveals the power
of disease to shape world history, to shape
economies, to shape politics, and it offers
lessons for the modern world in the face of
the myriad epidemic diseases that we are facing
today.
Thank you.
