Hi, Ira here. A lot of you have said, hey, Ira, we like the podcast, but sometimes we just want to listen to one story at a time. And we hear you. So we're going to try something new. A topic or two a day spread out through Monday through Science Friday. Have a listen.

Something like 40 to 50% of infections of the brain go without any known cause.

So what do doctors do when they can't figure it out?

They call Dr. Joe DeRisi.

It's Monday, October 9th.

Not to worry, though, it's still Science Friday.

I'm sci-fi producer Shoshana Bucksbaum. Remember that story from a few months ago about a woman who had a three-inch parasitic worm living in her brain? She's fine. They remove the worm. But in Dr.

Dureisi's world, brainworms aren't even that rare. Wait till he tells you about the brain-eating

amoebas. Flora Lickman goes behind the scenes of what it takes to crack medical mysteries.

Dr. DeRisi is a professor of biochemistry and biophysics at the University of California,

San Francisco, and the president of the Chan Zuckerberg Bio Hub, San Francisco.

Welcome to Science Friday.

Thanks for having me on.

So, Joe, let's get brainworms out of the way.

Are brain worms yet another thing I need to worry about, like climate change and a democracy

and now brain worms?

Flora, let me ask you this.

Do you wash your hands regularly?

Yes.

That's a great thing, because that's one of the most important things you can do to prevent

brain worms. A lot of these brain you can do to prevent brain worms.

A lot of these brainworns are actually pork tape worms. And if you really want to know the dirty

...