(NEXSTAR) – Doctors are being put on alert as a dangerous and potentially deadly parasite, the New World screwworm, inches its way closer to the U.S.
The screwworm has moved into the Mexican state of Tamaulipas, which is just across the border from Texas. The Centers for Disease Control and Prevention issued a health alert this week notifying clinicians and public health experts to look out for signs the parasite’s presence.
New World screwworm flies lay their eggs in wounds, noses, ears, eyes or mouths. Their eggs develop into parasitic larvae, or maggots, that feed on the surrounding flesh as they burrow deeper.
While they primarily affect livestock, they can lay eggs on and burrow into any warm-blooded animals – including people. If left untreated, the screwworm can be deadly to humans.
People are at the highest risk of being exposed to the screwworm if they spend time in areas where the flies are present, like Central America and Mexico, 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.
What are the symptoms of the New World screwworm?
The CDC advises clinicians to consider the possibility of a screwworm infestation if they see any of the following signs:
- Visible larvae or egg masses, which might be wounds, ears, eyes, noses, mouths or another body orifice
- Destruction of healthy tissue
- 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
How is a screwworm infestation treated?
To treat a screwworm infestation, the CDC advises clinicians to remove all the eggs and larvae from the person’s body. That may require surgery if the maggots are deeply embedded.
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.
The agency says there are currently no known cases of New World screwworm in the U.S., but concerns recently grew higher as the parasite approached the U.S.-Mexico border. The recent outbreak has affected about 148,000 animals and 1,190 people in Central America and Mexico.
