The New World screwworm infested a human in the U.S. for the first time in years and federal officials are working to prevent it from getting into the food supply.

A rare human case of a flesh-eating parasite known as New World screwworm has been confirmed in a Maryland resident as the Trump administration is trying to prevent the resurgence of an insect largely eradicated from livestock decades ago.

A screwworm is a flesh-eating parasitic blowfly. It lives on the living tissue of warm-blooded animals. It can live in a human, but it is rare.