The patient had traveled to Central America, where an outbreak of myiasis, an infection by screwworm larvae, has been ravaging livestock.

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

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.