Flesh-eating screwworm spreads across North America, 500 infected

A flesh-eating parasite that primarily affects livestock is spreading across Mexico and parts of Central America, with more than 500 human infections reported. The parasite, known as the New World screwworm (Cochliomyia hominivorax), is a type of fly whose larvae feed on living tissue. At least one human death has been linked to the infestation.