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 patient had recently returned to Maryland after traveling to El Salvador. The risk to public health in the US is very low.

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.