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!

Answer to Case 804

Answer to the Parasite Case of the Week 804: Brugia sp. microfilaria, favor B. malayi 

As noted by Idzi and others, this is a textbook example of Brugia sp. microfilaria, with beautiful terminal and sub-terminal nuclei and a characteristic long cephalic space. However, Idzi rightly recommends caution in committing to a species since B. malayi and B. timori can have a very similar appearance. He notes that "to decide which one, either geographical information is needed (B. timori is more restricted to the Lesser Sunda Islands of the Indonesian archipelago - from Bali over Timor to the Tanimbar Islands - while B. malayi is more widespread in South-East Asia), or information about the stain for the blood film (both Brugia species have a sheath in fact, but if the smear is stained with Giemsa, the sheath of B. timori is usually not visible).  

While we don't have an exposure history in this case, the stain is Giemsa, which points us to B. malayi. However, I consider the sheath staining to be a soft diagnostic feature, as I've seen this type of faint pink staining with Wuchereria, and not all B. malayi sheaths stain with Giemsa. 

Since the sheath staining is not reliable, we must use the other criteria for differentiating B. malayi and B. timori as follows: 

• B. malayi microfilariae are 175-230 micrometers long in stained blood smears, while B. timori microfilariae are ~310 micrometers. The current case appears to be in the former range, but it is a bit hard to tell from the image.
• B. timori microfilariae have a longer cephalic space and a more single file nuclei in the tail.
• Classically, the sheath of B. malayi microfilariae is deep pink on Giemsa-stained blood films, while the sheath of B. timori does not stain with Giemsa.

Given these features, I think we can make a tentative diagnosis of B. malayi, and try to obtain more clinical history.

Check out Idzi's previous beautiful cases of B. malayi and B. timori on this blog. You can find several more B. malayi cases by searching in the upper left-hand search bar.

The CDC DPDX also has some nice examples of B. malayi and B. timori.

Thanks again to Florida Fan for donating this beautiful case.

Case of the Week 803

For this week's case, we have a worm submitted from an otherwise asymptomatic teenager. No further history was provided. What is your identification, and how would you sign this case out?

Based on this gross examination, we dissected the worm and was able to get the following eggs: