New World screwworm is a fly that lays its eggs in open wounds and body opening such as the eyes, ears, nose or mouth. It primarily affects livestock and is rare in humans. It does not spread from person to person, and poses a very low risk to the public, according to U.S. health officials.

The New World screwworm is a type of fly that can cause widespread devastation to livestock, wildlife and pets.

The first human case in the U.S. of a flesh-eating parasite was reported in Maryland. The U.S. Department of Health and Human Services said a case of the flesh-eating New World screwworm parasite has been detected on Aug. 4 in a Marylander who had just returned to the U.S. after traveling to El Salvador.