Answer to Case 662

 Answer to theParasite Case of the Week 662:Fasciola/Fasciolopsis/Echinostoma species eggs. The clinical history is most consistent with infection with the liver fluke, F. hepatica, rather than infection with an intestinal fluke. As mentioned by Bernardino, Florida Fan and SB, Fasciola giganticais also in the differential diagnosis, based on the morphology of the eggs. However, it is not found in the Americas and can therefore be excluded.Fasciolaspp.,Fasciolopsis buski,andEchinostomaeggs have a similar appearance, measuring up to 130-150 in greatest dimension, and having a small operculum. In particular, the eggs of Fasciolaspp. andF. buskican be particularly challenging to differentiate, although the abopercular end of the former often has a roughened or irregular area. As noted by Sheldon, size matters in parasitology! The large size of these eggs allows similar appearing fluke and cestode eggs to be excluded from the differential. Fasciola hepaticahas an interesting life cycle. I would highly recommend checking out this really cool VIDEO onF. hepaticato see all of the different stages of theF. hepaticalife cycle.
Source: Creepy Dreadful Wonderful Parasites - Category: Parasitology Source Type: blogs