The first human screwworm case in the U.S. has been traced to a person in Maryland who traveled from Guatemala.

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

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.