This is Origin Stories, the Leaky Foundation podcast.

I'm Meredith Johnson.

Tuberculosis has been part of the human story for a very long time.

You might know it as consumption, a turn-of-the-century disease that conjures up images of pale, delicate women coughing into lace handkerchiefs.

In the 1800s, tuberculosis was causing death and suffering on an incredible scale.

In Europe and America, it caused one out of every seven deaths.

People didn't know what caused it.

They thought consumption maybe ran in families.

The only treatments were rest, fresh air, and sunshine.

And then on March 24, 1882,

a scientist named Robert Koch

astounded the scientific community

when he announced he had discovered the cause

of tuberculosis. It was a bacteria called mycobacterium tuberculosis. And this announcement

was a turning point in our battle against TB. Cook's discovery gave us an enemy we could fight.

It earned him the Nobel Prize and led to

advances in hygiene and eventually to the development of antibiotics that worked against the TB

pathogen. Now every year, on March 24th, organizations involved in the fight against TB

observe World Tuberculosis Day to raise awareness about this deadly disease.

On this episode of origin stories, we're marking World Tuberculosis Day with the first episode in a two-part series about how infectious disease has shaped human evolution.

We'll take a look at our deep history with tuberculosis and hear a surprising

story about the origins and evolution of one of the world's deadliest killers. And unfortunately,

...