Strongyloides stercoralis (threadworm) – Filariform larvae

Bottom: this larva is still sheathed in the molt, but exhibits a feature typical of Strongyloides stercoralis filariform larva, namely a notched posterior tip bearing 2 or 3 minute spines. Top: this tip’s feature is apparent on a exsheathed larva. The filariform stage follows the rhabdiform stage, and is infective.