Sunday, April 23, 2017

Case of the Week 443

This week's case was donated by Dr. Tom Grys. The patient is an immunocompromised man with hemophagocytic lymphohistiocytosis (HLH) and fever. He reports travel throughout the United States and Italy. Bone marrow biopsy revealed the following:


Sunday, April 16, 2017

Case of the Week 442

This week's case was generously donated by Dr. Bryan Schmitt and Kayla Kirby. The patient is a middle-aged man from West Africa who presented with a chief complaint of worms in his stool. Four tan-white objects were received in saline and an egg was expressed from one of them.


Saturday, April 15, 2017

Answer: Case 442

Answer: Taenia saginata proglottid and egg

This was a remarkable case in that the fresh proglottids clearly showed the characteristic uterine branching pattern without the need for clearing, mounting, or India ink injection. Instead, you can see all of the lateral branches coming off of the central uterine stem with surprising clarity:
By counting the uterine branches, you can differentiate Taenia solium from T. saginata/T. asiatica. 
Note that you should only count the primary branch points coming off of the central uterine stem. Also, it is important to count only on one side. As you can see from my line drawing above, there are ~15 branches that can be identified in this specimen, thus making this either Taenia saginata or T. asiatica. Given that this patient was from Africa, we can narrow the differential to T. saginata, the "beef" tapeworm. Upon questioning, the patient admitted to frequently eating undercooked beef, which is the route of human infection.

As a confirmatory measure, the proglottids were manipulated to release eggs like the one shown below, which confirm without a doubt that this is a Taenia proglottid. Note the characteristic morphologic features including internal hooklets (one is clearly seen) and thick outer wall with radial striations.
Here is a fun accompanying poem from Blaine Mathison:

If one eats undercooked meat in Africa it’s a general rule
It’s likely he will end up with proglottids in his stool!
As deeper into your ID you delve,
Count those branches more than twelve!
You’ll see it’s T. saginata, just like you learned in school!

Thank you again to Bryan and Kayla for donating this great case.

Monday, April 10, 2017

Case of the Week 441

This week's case was generously donated by Dr. Nipunie Rajapakse. The following object was passed in the stool of a teenage boy with recurrent fevers and constipation. His only travel outside of North America was Portugal and Hawaii. Treatment with an antihelminth was ineffective at alleviating his symptoms and follow-up stool exams were negative.


Sunday, April 9, 2017

Answer to Case 441

Not a parasite; most closely resembles a slice of onion/onion skin. If you do an internet search for sauteed onions, you will find many beautiful (and tasty looking) examples of similar-appearing structures.

This case is a great reminder that many food partially-digested objects can be seen in human stool specimens, and many of them (e.g. bean sprouts, bubble gum, citrus pieces, onion slices, tomato skins) can be seen an mistaken as parasites. The definitive way to differentiate these objects from true parasites is to look them under a dissecting microscopy and by light microscopy if necessary, examining the consistency and looking for eggs (as suggested by Michigan Micro).

Monday, April 3, 2017

Case of the Week 440

This week's case was from a young boy who had been unsuccessfully treated for pinworm infection. An apparent worm was submitted to the laboratory on a pinworm paddle (Swube®):

Given the unusual morphology, the specimen was cleared with Citrisolve and mounted on a slide for examination:

Identification? Many thanks to Florida Fan for donating this week's case!

Sunday, April 2, 2017

Answer to Case 440

Answer: Dipylidium caninum proglottid containing characteristic egg packets.

This is such a great case because it shows the characteristic morphology of this cestode, as well as how a clinical misdiagnosis (in this case, as pinworm) led to incorrect therapy, which was remedied following correct identification in the clinical microbiology laboratory. Thanks again to Florida Fan for donating this case. Here are some of the key features of this case:

Saturday, March 25, 2017

Celebrating 10 years of Creepy Dreadful Wonderful Parasites

Thank you for joining me today to celebrate 10 years of blogging with Creepy Dreadful Wonderful Parasites! I can't believe that my very first entry on this blog was posted on March 25, 2007.

For my celebration, I invited all readers to submit their artistic parasite creations, and was amazed by all of the outstanding entries I received. They are all below for your viewing pleasure. I entered the name of each person who submitted something into a hat and then randomly selected 5 names.
And the winners are:
  • Rachael Liesman
  • Sidnei Silva
  • Prakhar Vijay
  • Melanie Bois
  • Kevin Barker
I will contact each winner separately about your prize (choice of a parasite calendar, phone case, or mug).

Fabulous parasite creative works (by category):


Giardia and Leishmania, adorned in traditional Brazilian costumes. 
Illustrated by Sidnei da Silva

Trypanosoma brucei
Charcoal sketch by Emily Evans

Schistosoma couple
Painted on canvas by Prakhar Vijayvargiya

Tsetse fly and Reduviid bug
Illustrated by Amy Gallimore

Plasmodium berghei with a "Friday feeling Smile" by Kevin Barker

Looking for anisakids - a fish dissecting party with Rachel Vaubel, Melissa Blessing, Xuemei Wu, Emily Patterson, Melanie Bois and Heidi Lehrke

Cerebral toxoplasmosis by Melissa Blessing


Dipylidium caninum scarf by Heidi Lehrke

Giardia kiteii by Florida Fan

Leishmania cross-stitch by Tiffany Borbon

Dracunculus medinensis and myiasis cupcakes by Rachael Liesman

Plasmodium falciparum cookies by Emily Fernholz

Dermatobia hominis baby by Reeti Khare

Dipylidium caninum by Heather Rose

"Tubes of blood" for FIL (filariasis) and MAL (malaria) testing by Felicity Norris, Aimee Boeger and Brenda Nelson (note that Aimee is a green top tub (heparin) which we don't accept in my lab, so she has been 'cancelled'

Taenia solium with detachable 'proglottids' by Jadee Neff and family

Taenia solium and eosinophils with Rose Sandell and Melanie Bois

"Entamoeba histolytica/E. dispar/E. moshkovskii/E. bangladeshi and E. hartmanni - who can tell them apart?" with Patty Wright, Corrisa Miliander, Heather Rose, Emily Fernholz and Kelli Black

An engorged and gravid tick by Elli Theel

Giemsa by Jane Hata

A fish with a tapeworm by Rachael Liesman

by Blaine Mathison
Twas the night before Christmas when all through the house
the fleas were all nestled in the fur of the mouse.
They paired with their loved ones under a sprig of mistletoe,
A gift from Cousin Chigoe, from down south in the toe.

The larvae were pupating in the bed of the host,
carrying Dipylidium cysticercoids, an infectious dose!
The Yersinia pestis churned in the foregut
until such time when the proventriculus would erupt!

All of a sudden there appeared such a clatter!
The fleas sprang from the fur to see what was the matter.
Crawling up the leg of the host, with such stealth and so quick,
was the holiday icon known as St. Tick.

“Now Ixodes, now Dermacentor, and Amblyomma!
On RhipicephalusOrnithodoros, don’t forget Hyalomma.”
He got right to work and delivered the fleas' presents
full of pathogens to spread to medieval peasants,

Then he sprang to his sleigh and let out a whistle,
Then they took off into the night like a guided missile.
But I heard him exclaim as flew out of sight,
Merry Christmas to all, and to all a good bite!

Monday, March 20, 2017

Case of the Week 439

This week's case is anticipation of Saturday, March 25th, in which I will be celebrating the 10-year anniversary of Creepy Dreadful Wonderful Parasites. As part of the celebration, I am asking all readers to consider sharing a photograph of your parasite creations - be it a painting, photograph, parasite-related costume, poem or other creative work. I will enter the name of each person who submits something in a drawing and will select 3 winners for creepy dreadful wonderful parasite prizes.

I have already received multiple entries, and have chosen to highlight this excellent entry from Florida Fan - a parasite kite! Can you guess the parasite?

Sunday, March 19, 2017

Answer to Case 439

Answer: Giardia!

This lovely kite by Florida Fan was also identified as: Giardia kitelia, Giardia flier, and Giardia lampshadia

Be sure to check out all of the fantastic parasite creations that were submitted for my 10-year celebration.