Happy Valentine's Day! Here is a special photo taken by Emily Fernholz, my awesome education specialist. These 2 little worms were found in a concentrated stool specimen and measure approximately 250 micrometers long. Identification?
Answer: Strongyloides stercoralis rhabditiform larvae
As noted by Florida Fan and Sugar Magnolia, these 2 larvae are "intertwined in romantic interlude" - "performing a romantic ballet". Perfect for Valentine's day!
The identification can easily be made by the size of these nematodes, their short buccal cavities (arrows in image below), and the genital primordium (less easily appreciated here).
The patient is a 65 year old Spanish woman who brought 3 worm-like structures to her physician. She had expelled the structures 30 minutes prior to presentation, and one was noted to still be moving. She reports no travel outside of Europe.
As mentioned by Luis, Florida Fan, Atiya, and Sugar Magnolia, these proglottids can be differentiated by other large tapeworms by the size and shape of the proglottids, and the presence of more than 12 uterine branches arising from the central uterine canal/stem:
Remember when counting uterine branches to only count them as they come off the central stem (primary branches), and only on ONE side (not both)!
As some readers mentioned, the proglottids of Taenia saginata are morphologically indistinguishable from those of T. asiatica; however, the patient's lack of travel outside of Europe makes infection with this latter parasite unlikely. Thanks again to Idzi Potters and the Institute of Tropical Medicine, Antwerp, for this interesting case!
Every week I will post a new Case, along with the answer to the previous case. Please feel free to write in with your answers, comments, and questions. Also check out my image archive website at http://parasitewonders.com. Enjoy!
The Fine Print: Please note that all opinions expressed here are mine and not my employer. Information provided here is for educational purposes only. It is not intended as and does not substitute for medical advice. I do not accept medical consults from patients.