Answer to Case 696

 Answer to theParasite Case of the Week 696: Schistosoma haematobiumegg and larva (miracidium).As noted by Florida Fan, the morphology of the eggs is consistent withS. haematobiumandS. intercalatum,as both are ovoid with a terminal spine. However,S. haematobiumis usually found in urine, whereasS. intercalatumis usually found in stool. I didn ' t provide a size in this case, but it ' s helpful to know thatS. intercalatumis also usually longer thanS. haematobiumand has a central bulge.It is unusual to see a free miracidium in the urine. Note the circumferential cilia which gives it a shaggy appearance. TheOracle and Idzi mentioned that the presence of the free miracidium suggests a delay between sample collection and microscopic evaluation without preservation. Hatching ofSchistosomaeggs can also be triggered by dilution of the specimen in water. Idzi had previously donated a beautiful case of a motile miracidium to this blog, which you can seeHERE. Look how fast it is! This miracidium was also initially moving, but had stopped by the time we attempted to take a video. Thanks again to Felicity Norrie for these beautiful photographs!
Source: Creepy Dreadful Wonderful Parasites - Category: Parasitology Source Type: blogs