Case of the Week 499

Reminder - I am still taking parasite art submissions for Case of the Week 500! I will feature all artwork on my blog, along with the results of the drawing for 3 prizes :)

Now for this week's case, we have a very interesting submission from Dr. David Peaper. The patient is an elderly woman presenting with hematemesis. She underwent upper endoscopy and biopsies were taken from areas of erosion/inflammation. The biopsies were submitted for comprehensive vial culture, and the following were observed in the MRC-5 shell vials and traditional tube cultures.

Identification?

Answer to Case 499

Answer: Strongyloides stercoralis adult female worm and larvae.

The video shows both an adult and the larvae:

Capillaria philippinensis can have a similar presentation to S. stercoralis, with both adults and larvae present in the intestine; however, Capillaria is an obligate parasite and would not likely survive in the viral culture media for very long. If in doubt, you could differentiate C. philippinensis adults and larvae by examining good wet preparations of this specimen. Capillaria adults have a prominent stichosome whereas Strongyloides adults do not. Also, Capillaria rhabditiform larvae do not have a prominent genital primordium and clavate eosphagus like Strongyloides does. Unfortunately the buccal cavity is not clearly seen, but it appears to be relatively short.

Case of the Week 498

Dear readers, I will soon be posting my 500th Case. Hooray!! To celebrate, I would like to recognize the creativity of my readers by displaying a photograph of your parasite-related artwork on my blog. I will then put the names of all of the individuals who submitted a photo of their art in a hat and pick 3 names to receive a special parasite prize ☺ If you would like to send me a photo that I can post on my blog on July 2nd, please send it to b_pritt@yahoo.com

Now for this week's case - some beautiful eggs from my lab (images and video by Heather Rose):

Identification?

Answer to Case 498

Answer: Taenia sp. eggs. I forgot to mention that the stool specimen came from a human patient. Therefore, the main considerations are Taenia solium and Taenia saginata. If the patient acquired infection in Asia, then Taenia asiatica should also be considered. You cannot differentiate the 3 species based on the egg alone, instead, morphologic features of the adult worm (T. saginata/T. asiatica vs. T. solium) and molecular testing (T. saginata vs. T. asiatica) are needed. The photographs and video beautifully highlight the key diagnostic features:

As a side note, the eggs of Echinococcus species have a very similar appearance but would be found in the stool of infected dogs and other canids, and NOT in human stool.

Thanks again to Heather in my lab for the beautiful photos and video!

Case of the Week 497

This week's case was generously donated by Florida Fan. The following bug were submitted by the physician of a 69-year-old woman. No further history is available. As Florida Fan says, "Here comes the summer, and with it comes the bugs."

Identification?

Answer to Case 497

Answer: Cimex species; bed bug
As Blaine mentioned: "B&B Bugs is back! Beautiful brown biting, blood-sucking bed bug! Boo-yeah!" William mentioned that the pronotal hairs are not long enough to be a bat bug - an important consideration since bat bugs can be found near human dwellings and may bite humans when their preferred (bat) host is not available.

See Case of the Week 395 for more information and photos.

B&B Bugs = Bobbi and Blaine!

Case of the Week 496

Welcome to the first Monday of June 2018, and our case from Idzi Potters and the Institute of Tropical Medicine, Antwerp.

The patient is a 65-year-old owner of a camel farm who presents to his primary care provider for a yearly check-up. As he has mild intestinal complaints, he submits a fecal sample to be checked for parasites. The following structures were observed, and measure approximately 85 x 45 microns. Diagnosis please?

Concentrated wet preparation, 400x

Concentrated wet preparation, 400x with Lugol's iodine

Answer to Case 496

Answer: Trichostrongylus sp. egg
Congratulations to everyone who wrote in with the correct answer. Although this egg looks like those of the hookworms, Oesophagostomum spp., Ternidens spp., and Strongyloides stercoralis (latter only rarely seen in stool), the larger size (85 micrometers long) and tapered end points us towards Trichostrongylus.

This diagnosis is also supported by the history of camel exposure, as Trichostrongylus is primarily a parasite of ruminants. As Blaine mentioned, I should have posted this case on a Wednesday for 'hump' day!

William Sears also mentioned that the presence of eggs with well-developed larva indicates that the specimen likely sat for some time before being examined since the eggs are passed in human stool in an unembryonated state. Thanks again to Idzi Potters for donating this fascinating case.