Sunday, May 18, 2025

Case of the Week 777

 Dear Readers,

I am excited to announce that we are celebrating our 777th case! 

In honor of this milestone, we have a selection of 3 helminth eggs for you to identify. You win the parasite jackpot if you can get all three. There is an 'easy' and 'hard' version, so you get to take your pick.

EASY VERSION

Egg 1 (50 micrometers long)
Egg 2 (55 micrometers long)
Egg 3 (35 micrometers long)

HARD VERSION

Egg 1 (45 micrometers in diameter)


Egg 2 (95 micrometers long)

Egg 3 (One of 15 objects freed from a 4mm structure)


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24 comments:

  1. AnonymousMay 18, 2025 at 9:57 PM

    Trichuris.. Ascaris fertilized egg.. Taenia egg

    ReplyDelete
  2. AnonymousMay 18, 2025 at 9:58 PM

    Hard.. All 3 artifacts

    ReplyDelete
  3. AnonymousMay 18, 2025 at 10:01 PM

    Easy:
    1. Trichuris
    2. Ascaris
    3. Taenia

    Hard:
    1. Artifact
    2. Acanthocephalan (likely Macracanthorhynchus)
    3. Artifact

    ReplyDelete
  4. AnonymousMay 18, 2025 at 10:54 PM

    Easy
    1. Trichuris trichiura
    2. Ascaris
    3. Taenia
    Hard
    1,3 artifacts

    ReplyDelete
  5. AnonymousMay 18, 2025 at 10:58 PM

    So far I believe that the first egg is of Bertiella species. The second one is Macracanthorhynchus hirudinaceus. I don’t have the identification of the third one yet.
    Florida Fan

    ReplyDelete
  6. AnonymousMay 18, 2025 at 11:14 PM

    For sure the easy three are classic: Trichuris trichura, Ascaris lumbricoides/suis, and Taenia spp.
    Florida Fan

    ReplyDelete
  7. Idzi P.May 19, 2025 at 1:45 AM

    Splendid idea to do a quiz Dr. Pritt!
    Many congratulations!!!
    As for the answers to both quizzes:
    EASY:
    1. Trichuris trichiura
    2. Ascaris lumbricoides (fertile egg)
    3. Taenia spp. egg
    HARD:
    1. Bertiella egg
    2. Macracanthorhynchus egg
    3. egg capsule of Dipylidium caninum (with eggs inside of the dark area)

    ReplyDelete
  8. RamyaMay 19, 2025 at 3:52 AM

    This is so amzing

    Easy ones:
    1. Trichuris
    2. Ascaris
    3. Taenia

    Hard ones
    1. Bertiella- typical pyriform structure within the egg
    2. Egg of Acanthocephalan
    3. The hint says it all- Dipylidium caninum

    ReplyDelete
  9. Ira PraharajMay 19, 2025 at 4:45 AM

    Easy-
    1. Trichuris trichiura egg

    2. Ascaris lumbroides egg (fertilised)

    3. Taenia spp eggs

    Hard-
    Artifacts
    Spores

    ReplyDelete
  10. AnonymousMay 19, 2025 at 6:29 AM

    Idzi: I see what you mean, just the third object is so darkly stained that we can’t clearly visualize the internal structure. This confuses me.
    Florida Fan

    ReplyDelete
  11. AmandaMay 19, 2025 at 8:35 AM

    Easy:
    1. Trichuris trichiura egg
    2. Ascaris lumbricoides egg
    3. Taenia species egg

    ReplyDelete
  12. jebarnesMay 19, 2025 at 8:36 AM

    Easy:
    1. Trichuris trichiura
    2. Ascaris lumbricoides
    3. Taenia species
    Hard:
    1. Bertiella
    2. Acanthocephalan egg
    3. Stumped. The picture says comes from 4 mm structure but Dipylidium egg packets aren't that big. Waiting for the answer.

    ReplyDelete
  13. AnonymousMay 19, 2025 at 11:30 AM

    The proglotids of D. caninum when freshly passed out of my Scooby can measure up to 12*3 mm in size. Very shortly thereafter, they shrivel down to 4-6*1-2 mm and this size of a small rice grain is what we mostly find in the lab. It’s just the dark brown color rendered the internal structure not clearly visible and this is the challenge. Anyway this is a very good educational example otherwise the case would be a piece of cake.
    Florida Fan

    ReplyDelete
  14. AnonymousMay 19, 2025 at 12:09 PM

    Easy:
    1. Trichuris trichiura egg.
    2. Ascaris lumbricoides egg.
    3. Taenia sp egg.

    Hard:
    1. Bertiella sp egg.
    2. Macracanthorhynchus or Moniliformis egg.
    3. Inermicapsifer madagascariensis egg.

    Have my doubts, but wish it's ok.


    -HLCM fan

    ReplyDelete
  15. Idzi P.May 19, 2025 at 2:50 PM

    Waaauw! That’s amazing HLCM fan, you’re 100% right imo!
    That last one is indeed Inermicapsifer instead of Dipylidium.
    The size of 4mm fits right in with Inermicapsifer proglottids - better than with Dipylidium! Also the dark interior fits better…
    Nice! Congrats to HLCM fan!
    For the hard one nr.2 : moniliformis eggs would be more clear I think, so I’d go really for Macracanthorhynchus egg…

    ReplyDelete
  16. Idzi P.May 20, 2025 at 2:09 AM

    Another PS: Inermicapsifer and Raillietina cannot be morphologically differentiated without checking the scolex, so Railliettina sp. remains in the differential...
    My Final answers:
    EASY:
    1. Trichuris trichiura egg
    2. Ascaris lumbricoides (fertile egg)
    3. Taenia spp. egg
    HARD:
    1. Bertiella sp. egg
    2. Macracanthorhynchus sp. egg
    3. egg capsule of Inermicapsifer sp. or Raillietina sp. (with eggs inside of the dark area)

    ReplyDelete
  17. AnonymousMay 20, 2025 at 8:59 PM

    Congrats on 777!!! It's amazing the variations of things and presentations that come up -- very clever putting this blog together.

    As a mere people pathologist on the easy list I've seen and recognize trichuris, ascaris and taenia. On the hard list, if actually presented with an example, would have to give up and call in the pros - prelim "likely parasite present, ID to follow".

    ReplyDelete
  18. AnonymousMay 21, 2025 at 5:35 AM

    1 Trichuris
    2 Ascaris
    3 Taenia spp

    4-6 hard no pathogenic parasites seen
    /Patrik

    ReplyDelete
  19. AnonymousMay 21, 2025 at 7:03 PM

    Idzi: After reading all the answers and weighing the possibilities, I believe the answer is Inermicapsipher rather than Raillietina. So take your “leap of faith” “si Tu crois en toi”. 😀 Florida Fan

    ReplyDelete
  20. Idzi P.May 22, 2025 at 2:10 PM

    Florida Fan: sorry, I’m sticking with both options Florida Fan!!!
    😅😉
    I truly think you cannot make the distinction reliably based only on the egg capsule, I think you really need to look at the scolex (Raillietina=armed with hooks, while Inermicapsifer=unarmed).

    ReplyDelete
  21. Zahra MadaniMay 23, 2025 at 9:06 AM

    1. Trichuris Trichiura egg
    2. Ascaris Lumbericoides egg
    3. Taenia SP egg-tapeworm

    ReplyDelete
  22. AnonymousMay 23, 2025 at 9:40 AM

    Easy:

    1. Trichuris trichiura egg

    2. Ascaris lumbricoides egg

    3. Taenia sp. egg

    Hard:

    1. Bertiella sp. egg
    
2. Macracanthorhynchus sp. egg
    
3. egg capsule of Inermicapsifer/Raillietina.

    ReplyDelete
  23. Seyedmehdi MadaniMay 23, 2025 at 9:44 AM

    Easy:

    1. Trichuris trichiura egg

    2. Ascaris lumbricoides egg

    3. Taenia sp. egg

    Hard:

    1. Bertiella sp. egg
    
2. Macracanthorhynchus sp. egg
    
3. egg capsule of Inermicapsifer/Raillietina

    ReplyDelete
  24. AnonymousMay 31, 2025 at 2:14 AM

    1- Trichuris trichiura
    2- Ascaris lumbricoides
    3- Tenia sp. egg

    ReplyDelete