While rare in humans, the parasite is a major concern for livestock, with infestations capable of devastating cattle populations.

The CDC confirmed that a patient in Maryland, recently back from a trip to El Salvador, was diagnosed with a screwworm infection on Aug. 4.

The New World screwworm can be deadly for humans and animals, and can devastate livestock. The current risk to the public is said to be very low. The first case of a flesh-eating maggot in years has been detected in the United States,