(NEXSTAR) – After decades of eradication, the New World screwworm is back in the United States. Cases of the flesh-eating parasite have been confirmed in Texas and New Mexico, and officials fear its spread could wreak havoc on American livestock and cattle.
While the screwworm primarily affects livestock, cows and goats aren't the only ones vulnerable. The flies can lay eggs on any warm-blooded animal, including people and pets.
In fact, one of the confirmed cases in Lea County, New Mexico, is in a small pet dog.
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New World screwworm flies lay their eggs in open wounds, noses, ears, eyes or mouths. Those eggs develop into parasitic larvae, or maggots, that feed on the surrounding flesh as they burrow deeper.
If left untreated, the screwworm can be deadly to humans.
Earlier this year, as the screwworm began to make its way closer to the U.S.-Mexico border, the Centers for Disease Control and Prevention issued a memo advising clinicians to be on the lookout for possible signs of screwworm infestation.
Doctors and nurses were told to look for the following symptoms and signs:
Visible larvae or egg masses, which might be wounds, ears, eyes, noses, mouths or another body orifice
People reporting a sensation of movement in a wound or orifice
Foul odor, bloody discharge, swelling or pain around a wound or orifice
Recent travel to areas where the screwworm is present, like Mexico and Central America
To treat a screwworm infestation, the CDC advised clinicians to remove all the eggs and larvae from the person's body. That may require surgery if the maggots are deeply embedded.
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The clinician should kill all larvae and eggs in a patient with a suspected case of New World screwworm. They should also check back in 24 to 48 hours to make sure all the larvae and eggs were eliminated.
There are no studies to prove any specific medication could be an effective treatment, says the CDC.
People are at the highest risk of being exposed to the screwworm if they spend time in areas where the flies are present, and if they have open wounds like scratches or cuts. Those who spend more time outdoors and around animals are at the highest risk of exposure.
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