New ‘Flesh-Eating’ Screwworms, which are recognised as a parasite that eats cattle and other wild animals alive, are spreading in the US, after the Hantavirus and Ebola virus outbreaks. Due to these new flesh-eating worms, Washington has stopped cattle imports from Mexico for the past year. Here’s everything you need to know about these ‘flesh-eating’ screwworms in the US, and how dangerous they are.
What are Flesh-Eating Screwworms?
These flesh-eating screwworms are parasitic flies whose females lay eggs in wounds on any warm-blooded animal to which wild animals and livestock are becoming the victims in the US.
Once the eggs were hatched, hundreds of screwworm larvae use their sharp mouth to burrow through the living flesh and feed on it, which enlarges the wound and eventually kills the animal if left untreated.
Flesh-Eating Screwworms Outbreak in the US
Screwworms were eradicated from the US in the 1960s when researchers released massive sterilised male screwworm flies that mate with wild female worms to produce infertile eggs, and now again, authorities have found screwworms in the US, after 60 years.
In a post to social media on Wednesday, June 03, 2026, the U.S. Secretary of Agriculture, Brooke Rollins, confirmed the presence of Cochliomyia hominivorax, the New World screwworm fly, which is also known as the New World screwworm.
How to Identify Flesh-Eating Screwworms?
According to the Centres for Disease Control and Prevention, here’s how you can identify if there’s a screwworm:
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Seeing maggots within a skin wound or sore, or in the ears, nose, eyes, or mouth.
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Painful skin wounds or sores that worsen within days.
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A foul-smelling odour from the site of the infestation.
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Bleeding from open sores.
However, bacteria can also infect wounds where screwworm maggots are present, which may cause an infection that can lead to symptoms, such as fever or chills.
Are Humans at Risk in the US?
According to a veterinary medicine professor at the University of Minnesota, screwworms will feed on humans if they can.
Homeless people are at the highest risk, as they sleep outside and are less likely to maintain hygiene and medical care.
How to Prevent Screwworms?
Here’s how to prevent screwworms:
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Keep open wounds clean and covered, no matter how small or located on the body.
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Sleep indoors with closed windows.
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Protect your skin and prevent insect bites by using an EPA-registered insect repellent.
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Wear loose-fitting, long-sleeved shirts and pants, hats, and socks to limit access to your body.
How these ‘Flesh-Eating’ Worms Affect the Market?
As the cattle herd in the US was already at a low, the closure on imports elevated the record-high prices of beef by keeping more calves out of the US supply chain.
The first confirmed case in the US represents a serious challenge for ranchers, and it can cause a further rise in beef prices.
How US Avoid New World Screwworms?
The USDA has been preparing for a possible outbreak for some time and has taken several measures to ensure that screwworm infestation doesn’t take place.
The USDA created new monitoring, testing, and quarantine protocols in response to the outbreak spreading in Central and South America.
Moreover, a plan is also in motion to build a facility in Texas that will produce hundreds of millions of sterile flies each week, which is set to open next year.
