U.S. officials confirmed a case of the flesh-eating parasite in a person who traveled from El Salvador. Screwworm typically affects cattle in South America but has spread north in recent years.

The parasite — the larvae of the new world screwworm fly — can devastate cattle herds and is rife in parts of Central America.

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.