1st case of eye worms in humans reported
Abby Beckley thought her left eye was irritated because of a stray eyelash. She rubbed it, flushed it with water, but when the discomfort remained, she peered into the mirror. She thought she saw a piece of clear fuzz. She pinched it with her fingers and pulled it out.
It was a worm. “It was alive and squiggling around,” she recalled.
Ms. Beckley, — the focus of what is being called the first known human case of a parasitic infection spread by flies — was 26 and a deckhand on a commercial fishing boat in Alaska. At an urgent care clinic, the clinicians did not know what to tell her, but they pulled out twomore worms.
Luckily, her boyfriend’s parents, both doctors, got her an appointment with an infectious disease specialist in Portland, Ore.
In the end, it was a team of scientists at the Centers for Disease Control and Prevention that solved Ms. Beckley’s case, which took place in August 2016. They figured out she had been infected by a species of eye worm that had never before been found in a human. By the time her ordeal was over, 14 worms had been pulled from her eye.
Medical parasitologist Richard Bradbury identified the species by searching the medical literature and eventually finding an obscure journal written in German that was published in 1928. The case study about Ms. Beckley’s ordeal was published Monday in the American Journal of Tropical Medicine and Hygiene.
“We never expected to see this particular species in a human,” Dr. Bradbury said. Until now, this type of worm, Thelazia gulosa, had only been found in cattle in the northern United States and southern Canada.
Eye worms infect a variety of animals, but human infections are rare. The worms are transmitted to eyes by a type of fly known as “face flies.” The flies ingest the worm larvae, then land on an animal’s eyes, where the flies feed on tears and other secretions. During this process, the flies deposit the worm larvae into the eye, where they grow into adult worms.
In the weeks before her infection, she had been walking through cattle fields in her native southern Oregon and was often around cows and horses. It is possible, she said, a fly landed on her eye and infected her.