Thomas Goetz

Just as fish and birds and dogs and horses all get parasitic infections, so do we.

Many of these parasitic diseases started in the tropics.

Since about 1492, basically over the past 600 years of conquest and migration and slavery, parasitic diseases have spread around the world.

Parasites are everywhere.

Here's a factoid.

The U.S.

Centers for Disease Control and Prevention is based in Atlanta, Georgia, because 75 years ago, parasitic diseases were common in the Deep South.

It was mostly malaria, but also hookworm.

In fact, let's start our tale there, in the southern United States, with a story about hookworms, circa 1900.

Charles Stiles was born in New York and educated in the zoological sciences at the finest institutions in Europe.

Stiles was particularly interested in parasites in livestock, like trichinosis in swine and tapeworm in cattle.

At the time, the study of parasites, this is called parasitology, this was a brand new field of medicine.

Parasites, it was discovered, caused diseases like giardia and malaria, and compared to bacteria, parasites were easier to find, sometimes even visible to the naked eye without a microscope.

But that did not make them any easier to deal with.

So around 1900, Charles Stiles took a job as the chief zoologist for the U.S.

Public Health Service.

And when he heard about health problems in the American South, anemia, stunted growth, he had a hunch that parasites were involved.

So Stiles began to research.

Well, there's really no other way to say this.

He went on a study of human shit across the South.