The first case in years of New World screwworm infesting a human has been detected in the U.S. The infestation was detected in a person who had recently traveled to El Salvador and is being examined by the Maryland Department of Health and the U.

A rare case of travel-related New World screwworm was identified in Maryland in a patient who traveled from El Salvador, a spokesman from the US Department of Health and Human Services said.

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