An Oregon woman who had worms coming out of her eye is the first known human case of a parasitic infection spread by flies.
Fourteen tiny worms were removed from the left eye of the 26-year-old woman in August 2016, scientists reported.
Normally seen in cattle
The report was recently published in the American Journal of Tropical Medicine and Hygiene.
The woman, Abby Beckley, was diagnosed with Thelazia gulosa. That's a type of eye worm seen in cattle in the northern United States and southern Canada, but never before in humans.
However, two other types of Thelazia eye worm infections had been seen in people before, according to Richard Bradbury of the Centers for Disease Control and Prevention. He was the study's lead author.
They are spread by a type of fly known as "face flies". The flies feed on the tears that lubricate the eyeball, scientists said.
If the worms remain in a person’s eye for a prolonged time, they can cause corneal scarring and even blindness, according to the researchers.
She had been horseback riding and fishing in Gold Beach, Oregon, a coastal, cattle-farming area.
No additional symptoms
After a week of eye irritation, Beckley pulled a worm from her eye. Over the next two weeks, doctors removed 13 more.
The worms were translucent and each less than 1.27cm long.
After they were removed, no more worms were found and she had no additional symptoms.
Eye worms are seen in several kinds of animals, including cats and dogs. They can be spread by different kinds of flies.
Image credit: iStock