Case of the Week 808

This week's case is a worm that was reportedly vomited from a teenager and found in the toilet. What is your identification?

Many thanks to Felicity for taking these videos!

Answer to Case 808

 Answer to the Parasite Case of the Week 808: Nematomorph (a.k.a. gordian or horse hair worm), or similar appearing worm. As noted by an anonymous reader, this is "most likely nematomorpha but would need to examine under magnification. I have encountered many museum specimens labeled as horsehair worms that were in fact mermithid nematodes or haplotaxid annelids." 

Regardless of the definitive identification, the important thing to mention in the report is that this worm is NOT a human parasite. It was most likely found in the toilet and not actually vomited by the patient.

As discussed by Idzi, "The adults of the Nematomorphs are not parasitic (they live in water) but the larvae are parasitic and use terrestrial insects as their host. Once the larva inside the insect has matured (after several molts), the infested insect will have an irresistible urge to drown itself, thus bringing the adult worm back to water. Neat trick!" This is one of several parasites that manipulates the host to further its own life cycle - another being Toxoplasma gondii in the rodent host. 

I've featured this parasite a few other times on this blog, and have written a longer description that you can read HERE. This link will also bring you to other cases, including one with a very graphic video of a worm emerging from a cricket 😯. As described by Florida Fan, "What else can I say. The “equine chevelure” though not so “knotted" is very vivid?

Case of the Week 807

Happy Lab Week! In honor of this special week, I wanted to share these images from our long-time contributor, Florida Fan. He made these kites himself. Can you guess what parasite is represented?

Answer to Case 807

Answer to the Parasite Case of the Week 807: A beautiful Giardia kite by Florida Fan

We had a lot of great comments on this case. Many viewers commented on how 'cute' the kite was, and so easily recognizable. Some wanted to buy the kite for themselves - Florida Fan, you could consider starting a business! 

Here are few other comments that made me laugh:

1. Uni of Nomi said "It's a bird! It's a plane! It's Giardia!
2. Nicole De Young suggested flying a Flagyl (metronidazole) kite next to this one that says "We don't need G. lamblia here!"
3. Carlow Umlas asked if Giardia trophs are now airborne 😂
4. Daniel Prem Kumar suggested that this was Giardia kiteiaa, a new species on air
5. Société Française de Parasitologie declared this was the best parasitological image of the week!
6. Ali Abdolrasouit said "stunning! Next round Trichomonas?" (better start working on this, Florida Fan 🤓)
7. Sean G. Smith: "I think it might be related to this stump" (A definite likeness)
8. Janet Elizabeth Doyle: "I absolutely knew it was Florida Fan before I read it! Always with a great guess!
9. And last but not least, from Marisa Ginn: "Looks like Giardia--But much BIGGER! (Yikes, I hope I never meet this Giardia!)

Many thanks to Florida Fan for sharing his work.

I also want to give you all an idea for next year's Lab Week, courtesy of Brent Barrett - looks like fun! 

Case of the Week 806

This week's interesting case was donated by Race Rucki and Jason Shearer from the University of Vermont. The patient had recently returned from Belize and found this 'souvenir' in his neck. What is your diagnosis?

Answer to Case 806

Answer to Case of the Week 806: Myiasis-causing fly larva, consistent with Dermatodia hominis

As noted by Idzi, this is an "L3 larva of Dermatobia hominis. Typical are large and heavily pigmented spines that are arranged in neat rows. Also typical for L3 larvae of D. hominis is their general pyriform shape." 

Note the lack of spines on the terminal 3 segments, which is characteristic for this species. 

Definitive identification is through examination of the posterior spiracles, which are unfortunately a bit hard to see in this case. However, if you use your imagination, (and maybe squint a little bit), you can make out the 3 straight slits with just a slight curve to them, and can appreciate that they lack a peritreme:

Thankfully removal is curative. 

Some more wisdom from Idzi:

Fun knowledge fact: Dermatobia hominis flies will not deposit their eggs directly on humans but rather on a bloodfeeding insect, which will transport it to the human host during a blood meal! Therefore this type of myiasis will usually present on "exposed skin areas". In contrast, its African counterpart (Cordylobia anthropophaga) deposits its eggs usually on clothing that is drying outside, thus resulting in myiasis of usually the "unexposed" areas of the body: scalp (putting on a contaminated T-shirt), back, legs (putting on trousers),...

Thanks again to Race Rucki and Jason Shearer from the University of Vermont for donating this classic case!

Case of the Week 805

This week's case was generously donated by Dr. Karra Jones, and features H&E histopathologic sections of intestine from patient with intussusception. Upon close examination, the culprit behind the intussusception can be seen:

What is your diagnosis?

Answer to Case 805

Answer to the Parasite Case of the Week 805: Anisakis sp. larva

As noted by Idzi, "For sure the patient has consumed raw/undercooked fish, as this is one of the anisakids! Indeed the Y-shaped lateral chords are typical!" Anisakis species have Y-shaped lateral chords, whereas Pseudoterranova sp. have plumper, 'butterfly' shaped chords.

Here are the characteristic features, including the Y-shaped lateral chords - among the best I've seen:

SM noted that "The location seems to be the intestinal wall or mesentery. The worm penetrated the wall and caused granulomatous inflammation with eosinophils, leading to intussusception."

Thanks again to Dr. Jones for sharing this classic case!

Information Requested! ❤️

Dear Friends,

On behalf of the Parasite Morphology Hub of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), I'd like to invite you to participate in a short survey aimed at understanding current practices and diagnostic capabilities in morphological parasitology.

👩‍⚕️ Who should respond? Laboratories providing parasitology diagnostic services
⏱ Time required: ~8 minutes

Your inputs will help generate meaningful insights to improve parasite diagnostics and our future academic initiatives. The responses will be used for academic/research purposes only.

 Click the link 👇

🔗 https://forms.gle/pXdPYyesJMCmmMZt7

 We would greatly appreciate your participation and request you to kindly share this survey within your professional networks.

Thank you!

ParasiteGal

Case of the Week 804

This week's case is by Florida Fan, and represents a nearly 'picture perfect' representation of a particular filarial species in a peripheral blood smear. What is your identification? For students, residents, and fellows - this is a classic, and definitely fair game on exams!