7 Deadly Epidemics You Didn’t Know Existed

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I don’t want to go all John Green on you guys,  but the history of humanity is full of disease.

Even when you pay attention in history class,  

though, you usually only hear  about a few headliner events.

You got the Black Death in the 14th  century, the Spanish Flu in 1918…

…which actually was not Spanish in origin.  That’s not important right now, though.

Pathogens like the influenza virus and Yersinia  Pestis, the species of bacteria responsible for  

bubonic plague, have caused many epidemics and  pandemics that you may have never heard about.

And that’s kind of inexcusable.

So let’s break down seven of them across history,  

and learn why they were every  bit as awful as the famous ones.

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First, let’s address the difference  between an epidemic and a pandemic.

In general, experts use the  word “epidemic” where a certain  

geographic area sees an unexpected  increase in cases compared to normal.

While “Pandemic” is used for skyrocketing  increase over a broader population and location.

But usually there’s no clearcut threshold for the  

exact number of cases that pushes  an outbreak into either category.

Public health officials just have to keep an  eye on the typical disease numbers in an area,  

and compare what they’re observing now.

With that little lesson out of the way, let’s  start with the oldest epidemic on our list,  

which features a virus we know all too well.

If you’re like most of our audience,  you were born before the 21st century,  

and you’ve already lived through  multiple coronavirus epidemics.

But unless you look very, very good for your age,  you definitely did not experience the first one

Because our earliest evidence of a coronavirus  epidemic dates to around 23,000 BCE in East Asia.

Now of course we do not have  any first-person accounts.

But to explore our ancient  past, scientists can study  

our modern genetic code and kinda work backwards.

In a study published in 2021, one research  team looked at over 2,500 human genomes  

across 26 global populations to look for  evidence of ancient coronavirus epidemics.

Specifically, they were looking for  parts of the human genome that code  

for certain virus-interacting proteins, or VIPs.

And like that acronym suggests,  VIPs are Very Important Proteins.

But not in a good way.

For example, some are proteins on the outsides  

of our cells that viruses use  to attach to and infect them.

So any evidence of VIP evolution could  

suggest some past viral epidemic  caused the proteins to adapt.

In other words, people with VIPs that the  viruses couldn’t latch onto as easily were  

more likely to not die before passing  their genes to the next generation.

For this study, scientists were looking  specifically at VIPs that are known to  

interact with coronaviruses…although that does  not mean they only interact with coronavirus.

Hence my use of the word “could”.

But based on the genetic evidence, and  some fancy computer models to estimate  

when certain mutations must have  originated, the researchers found  

significant adaptation in coronavirus  VIPs dating back roughly 900 generations.

They also found that most of the  oldest genetic adaptations seem  

to have happened in the ancestors  of modern East Asian populations.

Together, the evidence suggests ancient  humans in what is now East Asia probably  

experienced a coronavirus epidemic  somewhere around 25,000 years ago.

This is… very cool that we can find  evidence for epidemics that happened  

thousands of years before we  could even write about them.

But learning about the evolutionary  history of humans’ response to