Second Case Of Parasitic Eye Worms Now Discovered

Imagine finding out you have parasitic eye worms living inside your eyeballs like in the TV series, The Strain.

If I found a worm slithering out of my eyeball, I would completely lose it.

However, a 68-year-old Nebraskan woman seems to be made from stronger steel than me.

This is because she waited until the third worm popping out of her right eye before going to the doctor. Later, it was found that she is the second-ever human victim of this species of worm.

Parasitic Eye Worms

The concern, in regards to this human parasite, is that this incident may be a prelude to the emergence of a new parasitic disease in the United States.

How Was She Infected With The Parasitic Eye Worms?

The 68-year-old was running along a trail in Carmel Valley, in February 2018 while visiting California.

When on a morning run along a forest trail, she ran into a large swarm of flies. She swatted the flies away from her face and continued on with her run.

However, unbeknownst to her, the flies she ran into were not your average garden variety flies. Instead, there were Musca autumnalis flies, better known as face flies (1).

For the most part, these files are considered pests. This is because they hover around the eyes and drink tears from cattle and other animals.

When the woman returned to Nebraska a month later, she experienced some irritation in her right eye. When she looked in the mirror, she found horror staring back at her. It was a translucent roundworm about half an inch in size that was swirling around her eyeball.

Dr. Richard Bradbury from CDC’s Parasitic Disease Reference Lab 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.”

Apparently, while swatting the many flies off her face, one managed to land on her eye for a few seconds to lay larvae.

Dianne Travers Gustafson is one of the experts who have studied this second incident in the US and are trying to find out if there’s more in store for us (2).

The First Case Of Human Parasitic Eye Worms In The US:

Abby Beckley And The Parasitic Eye Worms In Her Eyes

The report on the first case of the cattle eye worm is published in The American Society of Tropical Medicine and Hygiene (3).

This case had a 26-year-old female (Abby Beckley) in Oregon that had to have 14 worms removed from her left eye. The perpetrators were identified to be the Thelazia gulosa worm, also known as the cattle eyeworm.

Experts are concerned with this development because the cattle eyeworm, as the name suggests, usually only affects cattle.

But now that one (now two) humans have been infected, will there be more cases reported over the next few weeks or months?

What Is The Thelazia Gulosa (Cattle Eyeworm)?

The Thelazia gulosa is the third species of Thelazia to be able to infect a human eye.

According to Dr. Bradbury, he needed to dig out a 1928 research paper (in German) to identify the strain of worm. It’s just that rare.

These worms mature in the face fly’s digestive tract and move to the fly’s mouthparts in their late-stages.

The worms infect the tear ducts of the victims when the face fly lands on their eyes. The most common known victims of this parasite are cattle, dogs, and horses.

After they transform into adults and produce more larvae, they are picked up by another face fly to continue the whole cycle again.

Thelazia Gulosa Cycle

However, this wasn’t possible in this woman’s case since there were no face flies to continue onto the next stage.

What ended up happening is that the adult eye worms were forced to come out of the eyelids. This happened when she squeezed her inflamed eyelid which had swollen due to the infestation.

The only saving grace about Thelazia gulosa is that the parasitic eye worms don’t burrow inside the eyeball.

Even then, none of us would be relieved if we were told that there we were infected with parasitic eyeworms.

Is The US Under Threat From Parasitic Eye Worms?

While this isn’t a national threat, keeping our eyes peeled to see how the situation evolves is very important.

In regards to the emergence of this parasite in the US, Dr. Bradbury said, “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.”

The CDC advises anyone who thinks that may have eye worms should immediately seek medical help to confirm, identify, and remove the worms (4).

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Jessica J
About Jessica J 133 Articles
Written & Reviewed by Jessica J, M. D. Dermatology.

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