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

A human case of a flesh-eating parasite known as New World screwworm has been confirmed in a Maryland resident, the first in the United States in years, according to U.S. and state health officials.

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.