Happy Halloween to all my readers! This week's case will be a be a bit unusual. I had my annual Halloween party last night and had a great turn out from my lab and our pathology and microbiology trainees. Here are some of the top parasitology costumes. Can you guess their identity?
Thank you readers for giving your best guess for what my lab staff and trainees were for Halloween! Here are the answers:
Mommy Taenia solium and her 3 motile proglottids. Note Jaydee's hooked rostellum, 4 suckers and proglottids of increasing length (arrows).
As an interesting coincidence, these 2 ladies also came as T. solium with accompanying eosinophils for their dates. Each have 3 proglottids in their costume. Near the end of my 'wild' parasite party, the eosinophils degranulated and the parasites had to fend for themselves.
My lead tech and parasite queen extraordinaire came as a D. caninum egg packet containing ova with appropriately hooked onchopheres.
We also had a little parasite who couldn't make it to the party but was too cute to leave out: a little Dermatobia hominis
The following case was donated by Dr. Tess Karre. This was an incidental finding in sections of duodenum that had been removed during a gastric restrictive procedure from a 50 year old morbidly obese patient. There was no travel history outside of the United States.
Answer: Cross-sections of Enterobius vermicularis adults in the duodenum. Although this is an unusual location for this worm, the characteristic lateral alae and features of an adult worm (internal organs including intestine and testes) allow us to make the diagnosis. E. vermicularis is the only adult worm found in humans that has lateral alae (although various larvae may also have lateral alae).
From Blaine Mathison:
While the duodenum is an unusual
place to find this worm,
the morphologic features
shouldn't cause you to squirm
Answer: Lucilia sp. ("green bottle fly"), a genus of blow flies in the family Calliphoridae
This was a bit of a challenging case. When it comes to bot flies, the overall body shape and, in particular, features of the spiracular plates, are used for identifying the genus of the infesting fly. In this case, the peritreme of the spiracular plates is complete, the button is clear and the slits are straight (below), which is consistent the with Lucilia species.
Some readers suggested that this could be Cochliomyia hominivorax, the New World screw-worm. However, the peritreme of this fly is incomplete and the button is not clear as what is seen in this 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 medical education only. It is not intended as and does not substitute for medical advice. I do not accept medical consults from patients.