What should you do if you think you might be harboring a nematode?

In the first place, the odds are against it. The worm that Jon Allen extracted from his mouth is only the 57th Gongylonema pulchrum known to infect a human. Allen and his collaborator Aurora Esquela-Kerscher suspect that many more of us are hosting one of these worms, but even if the incidence of infection is greater by a couple orders of magnitude, gongylonemiasis in humans would still be a mere medical curiosity, running below the radar of the medical community.

Therefore: Expect your health providers to be skeptical.

Allen couldn’t convince his oral surgeon, even though he arrived at the office armed with scientific literature and photos showing the worm had moved near his lip. Allen and his worm made the rounds of William & Mary’s Department of Biology. His colleague Matthias Leu was open-minded enough to go down the hallway to the men’s room where they both peered into Allen’s mouth via the mirror. Leu was surprised at the oral surgeon’s negative diagnosis.

“You would think when you have an invertebrate biologist in your office, with pictures and papers, you’d pay a little more attention,” said Leu, who has made Allen story’s a set piece in his Conservation Biology classes. “I tell it with a lot of drama,” he says. “Everybody laughs and laughs.”

Finally, take comfort in the fact that among the parasites in the world, Gongylonema pulchrum is not that bad. The worm Allen extracted, less than an inch long and about as thick as a piece of sewing thread, was a fully mature specimen. There are anti-nematode drugs available, but he’s opted not to take them. Remember, Allen reported no symptoms other than that annoying rough spot that migrated strangely around his mouth.

“It’s a super-rare invertebrate parasite that’s also totally harmless,” he says.

“So far as we know,” Esquela-Kerscher adds.