When I first heard the clinical idiom "When you hear hoof-beats, think horses not zebras" I thought it was a precautionary saying about the bias toward assuming the familiar. But it's meant to be instructive!

No, that’s backwards. It means what it says. When you see a symptom first look for the common things it could be, not the one in a million chance.

We have a formal description of this, it's called bayes theorem.

The Jordanian doctors just had poor priors.

In this particular case, "when you see stripes with hoofbeats, think zebra, not horse with a paintjob"

Friend did a lot of work in Africa. Got back to the US and starts getting symptomatic and says to himself “I think I got malaria”.

Goes to the biggest university hospital nearby he can find.

Was initially dismissed but waited it out for the infectious diseases specialist and they quickly agreed with his self-diagnosis.

They kept them in hospital for a few days so a parade of clinical students/residents could come by for the specialist to say: “this man has malaria”

I came back from Bali and shortly after came down with a really high fever when I was on vacation in Maine. When I got home week later called my primary as I was still running a bit of a fever and got blood work which was pretty bad. Went to ER and my primary care figured it was something tick related. The infectious disease guy on call immediately identified as Dengue Fever. At the end, including sending blood to the Louis Pasteur Institute in Paris I spent something south of $1K to get told I’d recover on my own—the Paris tests came back like weeks later—and there really wasn’t much they could do.

Weird. Pretty much every time I've gone to a doctor (in the Midwest US, no less) for an illness, the second question they ask is always "have you been out of the country recently?" just to rule out anything caught from abroad.

Then again, my one experience with a university hospital was pretty shitty, so maybe that's it?

This was decades ago, so maybe getting asked regularly nowadays was because of that previous education.

I had a weird cardiac issue, for which they kept me in the hospital for a few days and brought in more and more doctors to hear my story. Added tens of thousands to my bill. Eventually checked myself out "against doctor's advice".

A good family friend caught abdominal TB while abroad, came back to Canada, and was terribly misdiagnosed. TB is very rare here; abdominal TB even more so, and early symptoms look like a lot of other diseases. It took several hospital visits before the doctors realized the actual problem. He very nearly died, and spent nearly a year in the hospital recovering from a parade of complications.