Note below that they are here with us as well. Pete 
"There are two types of screwworm flies: Old World (Chrysomya bezziana) and New World (Cochliomyia hominivorax). “Hominivorax,” by the way, means “man-eater.”
Old World screwworms are present throughout Africa, Southeast Asia and several countries on the west coast of the Persian Gulf. Meanwhile, the New World species sticks to the western hemisphere. They have similar parasitic needs and nearly identical lifecycles.".......
http://www.pbs.org/newshour/updates/7-r ... you-think/