New Delhi: A tiny worm species till now only seen in cattle has been found inside the eye of a US woman for the first time.
Abby Beckley from Oregon has become the first person worldwide known to have had an eye infestation by the worm, that is spread by flies that feed on eyeball lubrication.
Scientists at the US Centers for Disease Control and Prevention extracted 14 translucent parasitic worms of the species Thelazia gulosa, all less than half an inch (1.27 cm) long, from the 26-year-old woman's eye over a 20-day period before her symptoms dissipated.
This species of Thelazia worm was previously seen in cattle throughout the northern United States and southern Canada, the researchers reported in a study published in the American Journal of Tropical Medicine and Hygiene. They said the study indicates that North Americans may be more vulnerable than previously understood to such infections.
According to researchers, the worms can cause corneal scarring and even blindness if they remain inside a person's eye for a long time.
"Cases of eye worm parasitic infections are rare in the USA, and this case turned out to be a species of the Thelazia that had never been reported in humans," said study lead author Richard Bradbury, who works with the CDC's Division of Parasitic Diseases and Malaria.
It was previously thought that there were only two different species of these eye worms that infected humans worldwide, Bradbury said. But now, Thelazia gulosa is the third.
Abby felt irritation in her left eye, which she thought was due to a stray eyelash that might have found its way inside the eye.
She rubbed and washed her eye with water, but the discomfort remained. As she looked closely in the mirror, she noticed a small, translucent worm. She pinched it and pulled it out.
Her frequent outdoor pastimes during the summer months exposed her to the infection, researchers said.
She was from the city of Gold Beach, located on Oregon's coast along the Pacific Ocean about 40 miles (65 km) north of the California border.
Previous cases of such eye worm infections have been reported worldwide, predominantly in Europe and Asia and in rural communities with close proximity to animals and with poor living standards, the researchers said.
Eye worms are found in a variety of animals including dogs, cats, and certain wild carnivores.
(With inputs from Reuters)