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.

Health officials confirm that a Maryland resident was diagnosed with New World screwworm earlier this month after traveling to El Salvador. It has been declared the first human case in the United States by the Centers for Diesease Control and Prevention.