Sunday, June 29, 2014

Answer to Case 309

Answer:  Schistosoma haematobium ova/eggs

Everyone who wrote in had the correct answer.  These eggs have a very characteristic appearance with a large size (112 - 170 micrometers in length) and terminal spine.  As mentioned by Hans, you can check to see if the eggs are still viable by looking for the internal beating flame cells, particularly in fresh specimens. Unfortunately this specimen was several days old by the time it had reached us (it had been sent in from another lab as a consult) and no motility was observed - possibly due to the age of the specimen.  Hans also mentions that you can hatch the eggs - that's always something fun to do!

Anon noted the considerable debris that was present in the background.  Indeed, one of the reasons I chose this case for a blog post is because it had a lot of crystals in the background which can make it challenging to spot the eggs. This is seen occasionally with refrigerated specimens; gently heating them will often dissolve the crystals and allow the urine to be examined for parasite eggs.  Some types of urine crystals are commonly seen and do not necessarily indicate disease.  However, other types of crystals are strongly associated with disease - particularly when persistent.  When in doubt, consult your Clinical Chemist or suggest that a urine specimen be sent for crystal analysis.

No comments: