The worms are genetically indistinguishable from the "Dracunculus medinensis" that infects humans. The life cycle of "Dracunculus medinensis" has been show to have multiple life stages. In humans, the only known cause is "Dracunculus medinensis". Of Nematodes, the "Onchocerca volvulus", "Necator americanus", "Wuchereria bancrofti" and "Dracunculus medinensis" are human parasites. A second, potential candidate for deliberate extermination is "Dracunculus medinensis", the guinea worm. Other insects reported are "Dracunculus medinensis" (Guinea worm) and "Necator americanus" (hook worm).