Nebraska Woman Gets Infected By A Rare Parasitic Eye Worm

“It does raise the possibility that something might have changed in the ecology of T. gulosa in the USA.”


It may sound a bit weird – taking almost an inch-long worm out of your eye. And this has actually happened to a 68-year-old woman from Nebraska, who contracted a rare parasitic eye infection while she was running along a trail in Carmel Valley, California, last year.

Her weird incident has signaled that it could become an emerging parasitic infection or “zoonotic disease” in the United States. Her case was published last month in the journal Clinical Infectious Diseases. The woman’s doctors and researchers from the U.S. Centers for Disease Control and Prevention (CDC) contributed to her case.

According to sociologist Dianne Travers Gustafson from Creighton University in Nebraska, the woman was running along a trail and she went straight into a swarm of flies in February 2018. Unknowingly, she ran into a particular kind of fly called the face fly. And a month later, she had irritation in her right eye, which eventually led her to discover a tiny translucent worm from her eye.

Lead author of the case and parasitologist with CDC’s Parasitic Diseases Reference Lab Dr. Richard Bradbury said, “The vector fly will expel larvae onto the surface of the eye or the conjunctiva while feeding on lacrimal secretions (tears, etc.). This can happen very quickly, so the fly would not have had to sit on the eye for more than a few seconds to expel the larvae.”

He told Gizmodo, “Normally people would shoo any flies near their eyes away before they could do this, but in this case the patient had run into so many flies at once that she could not shoo them all away before one expelled larvae onto her eye.”

Dr. Bradbury and his team discovered the worm was a member of the species called Thelazia gulosa, aka the cattle eye worm, which is quite rare.

The Nebraska woman is not the first person to have such an incident. In 2016, a woman from Oregon ended up having nearly 14 cattle eye worms, making her the first person to have been infected by Thelazia gulosa.

“While it may just be a ‘fluke’ event that two cases have occurred within a year or two of each other, it does raise the possibility that something might have changed in the ecology of T. gulosa in the USA to cause it to start occasionally infecting humans,” noted Dr. Bradbury.

The CDC parasitologist advised, “It is also really important that anyone who thinks they might have worms in their eye should go and see a qualified medical doctor for help.” “The doctor can arrange to send any worms recovered from the eye to a parasitology reference laboratory for identification to see if they are T. gulosa. This way, we can know if any more human infections like this happen,” he added.