Case of the Week 557

This week's case was donated by Florida Fan and one of his coworkers who found this beauty in some fresh salmon:

Posterior end:

 Anterior end:

Identification?

Case of the Week 556

This week's case was donated by Dr. Neil Harris and Dr. Stacy Beal. The patient is an infant with a history of tracheobronchomalacia and "eosinophilia" on prior bronchoscopy. A routine complete blood count was negative without evidence of peripheral eosinophilia. The following structures were seen on a Giemsa-stained bronchoalveolar lavage specimen using the 100x objective. They have a diameter of 1-3 micrometers. Identification?

Answer to Case 556

Answer to the Parasite Case of the Week 556: Curschmann spirals

Curshmann spirals can be a very pretty, but sometimes confounding parasite mimic in sputum, BAL and bronchial lavage specimens. They are spiral-shaped plugs of mucus from obstructed bronchioles, and are seen in patients with asthma and other conditions affecting the airways (e.g. tracheobronchomalacia as seen in this case). Although they can take on a roundworm-like appearance, they can be differentiated by their lack of defined morphologic features such as a cuticle and internal structures. Here is a striking photo from a different case (Papanicolaou stain):

Case of the Week 555 - a Special Challenge!

Dear readers,
I am excited and humbled to be posting my 555th Parasite Case of the Week. I am continuously inspired by your comments, questions, and the rich discussion that occurs with each post. To mark this occasion, I'm asking you all to comment on ways that parasites relate to the number 5. I'll start you off with two that were previously suggested to me when I thought up this challenge:

1. Pentatrichomonas hominis is a nonpathogenic intestinal flagellate named for its 5 flagella (penta from the Greek pente, meaning five + trich, pertaining to hair [flagella]). By Dr. Neil Anderson
2. There are 5 lobes of the human lung, and all can be infected by Paragonimus species. By Brian Duresko

Feel free to be as creative as you'd like. 5-lined poems (e.g. limericks) are also accepted! I will post all of the responses next Friday, so you have all weekend and next week to think of ideas. Enjoy!

Answer to Case 555 - Parasites and the Number Five

Wow - we received so many excellent comments on how parasites and the number 5 go together! Here are many of them - in no particular order - for your viewing pleasure:

1. Pentatrichomonas hominis is a nonpathogenic intestinal flagellate named for its 5 flagella (penta from the Greek pente, meaning five + trich, pertaining to hair [flagella]). By Neil Anderson and Bernardino Rocha.
2. There are 5 lobes of the lung, and all can be infected by Paragonimus species. By Brian Duresko.
3. The are 5 Plasmodium species that are responsible for the bulk of malaria in humans: P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi (the latter is a zoonotic parasite and important cause of malaria in regions of SE Asia). By Aimee Boerger, Nipunie Rajapakse, and LS.
4. Pentastomes have a name meaning "five openings". Although having a single mouth, there are 2 pairs of hollow fang-like hooks beside the mouth. These fangs can be retracted into slits giving the appearance of 5 mouths. By Old One.
5. Quintan fever, also known as trench fever, is due to infection with the bacterium Bartonella quintana, and is transmitted by the body louse, Pediculus humanus humanus. The infection is characterized by fevers that recur every five days; hence the name of the bacterium and the resultant disease. By Kristin Nagaro.
6. The gametocytes of Plasmodium vivax appear in the blood ~5 days after the liver stage, whereas it takes 10-12 days for P. falciparum to appear. Thus, P. vivax infection can be acquired by mosquitoes at the very first blood stage cycle, and this may confer a transmission advantage for P. vivax over P. falciparum. Plasmodium vivax has the most widespread distribution of the human malaria-causing Plasmodium spp., and the early gametocytemia will have important implications for malaria eradication. By BW in Vt.
7. Pentamidine is a drug used to treat some protozoal infections such as leishmaniasis and African trypanosomiasis. The first part of the drug's name comes from the pentane component which has 5 carbon atoms (C5H12). By Andy Norgan.
8. Human parasites can be divided into 5 major groups: protozoa, platyhelminthes, acanthocephala, nematoda, and arthropoda. By Bernardino Rocha.
9. The 5 main symptoms of giardiasis are diarrhea, abdominal pain, fatigue, weakness, weight loss. By bks. I use a similar one - the 5 "F's" of giardiasis: Foul-smelling Fatty Feces that Floats and Flatulence.
10. The US Centers for Disease Control and Prevention has targeted 5 neglected parasitic infections (Chagas disease, neurocysticercosis, toxocariasis, toxoplasmosis, and trichomoniasis) as priorities for public health action, based on the numbers of people infected, the severity of illnesses, or our ability to prevent and treat them. Anonymous.
11. Toxoplasmosis, a protozoal infection, in one of the ‘infamous 5’ TORCH infections that cause congenital abnormalities; the acronym stands for Toxoplasmosis, Other (syphilis, VZV, parvovirus b-19), Rubella, CMV, and Herpes simplex virus infections. By Vik Holenarasipur and Anonymous.
12. Human bot flies (and other insects) have 5 eyes - 2 are compound and 3 are simple. This paper wasp (below) is not a parasite, but was willing to pose for a photograph of its five eyes. By John Carlson (@JohnCarlsonMD).
    

There were also some wonderful stories and poems with 5 lines or words/line:

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From Blaine Mathison:

Many of the earth-based religions use the pentagram to represent the Five Elements: Spirit, Air, Water, Earth, and Fire. Many religious beliefs are grounded in scientific phenomena that were unknown at the time. What many people do not know, is the earth religions are rooted in Parasitology!

Spirit represents Loa loa and its microfilariae that circulate in the body. This belief is shared with Voodoo as the term 'loa' is a spirit in Voodoo religion.

Water represents Schistosoma, as water is natural reservoir for which the spirit enters the body.

Fire represents Trichomonas vaginalis, as people occupied by this spirit often have a burning sensation.

Earth represents Strongyloides stercoralis as they enter the body from the soil. Some liken Strongyloides to Mother Earth as she can create life in a host without a male counterpart.

Air represents Plasmodium, as it is carried by flying arthropods! And its erythrocytic cycle created periods of suffering and relief, as a reminder Life is a balance of Good and Evil.

If you have read this far, yes I am being silly and having fun, letting the creative juices overflow a bit :-D

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From Old One:

Now in Rochester’s sunny clime

Where I used to spend me time

A-servin’ the majestic Clinic Mayo

Of all that brilliant crew

The finest Doc I knew

Was Dr. Pritt, Diagnostic Mistro

It was Dr. Pritt, Pritt, Pritt

Most skillfull Parasite Gal, Dr.Pritt

Hi! Slippy Hitherao

Diagnosis please, Panee Lao

And be quick, about it. “Lickety split” Dr. Pritt

This noble Parasite Gal

Has a blog that’s really swell

Which has been followed round the globe for many years

She’s now at 555

And if I stay alive

I expect to see 666. Note to Satan, please stand clear

If I’m ever on campaign

Licking boots and water green

I will make tracts to Dr. Pritt at Mayo Clinic

She’s the one to check my blood and stool

Mama didn’t raise a fool

For I’ll surely have a case most parasitic

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Also from Old One:

Zen queries to Madam Ascaris

What is the sound of one hand clapping?

What does a three lip smile look like?

A happy worm is the ascarid

Swims in chyme and squirms like a squid

As happy as she is

She has but one regret

“How do you smile with three lips on the tip of ones head?”

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From Sir Galahad,

5 verses of J.Swift:

Big fleas...

Big fleas have little fleas

Upon their backs to bite' em

And little fleas have lesser fleas

And so, ad infinitum

(Filastrocca di Jonathan Swift

Disegno di Robert Hegner, 1938)

Case of the Week 554

This week's case was generously donated by Florida Fan. The following are seen on Giemsa-stained thick and thin blood films. No history is immediately available. Diagnosis? Any additional information you would like?

Answer to Case 554

Answer to Parasite Case of the Week 554: Babesia species. Without a travel history, the differential diagnosis includes Plasmodium falciparum malaria given that only ring forms are seen and there is a high parasitemia; however, the following features are supportive of babesiosis:
1. Multiple (4) small forms within a single cell that are not a clear schizont form of Plasmodium.
2. Easily-identified extracellular forms.
3. Lack of malaria pigment

As Blaine mentioned, the rings are not thin and delicate as would normally be seen with P. falciparum infection. While thicker rings are commonly seen in 'older' blood (i.e., blood that was >24 hours old), we would expect to see malaria pigment in these cases, and none is seen in this case.

One reader was favoring babesiosis, but was swayed from this diagnosis by the lack of maltese cross (tetrad) forms. However, it's important to note that most cases of babesiosis will NOT have maltese cross forms. Instead, the diagnosis must be made on the other features listed above, in addition to the commonly-seen pleomorphism of the parasite forms in babesiosis. Interestingly there wasn't a lot of pleomorphism in this case.

Thanks again to Florida Fan for donating this informative case. It reinforces the need to get a travel history whenever possible (he later learned that the patient had not traveled outside of the United States), and to consider both babesiosis and malaria in the differential when seeing intraerythrocytic parasites.

Case of the Week 553

This week's (interesting but somewhat disturbing) case was generously donated by Dr. José A. T. Poloni. The following was submitted from a fresh (unfixed) stool specimen. Most likely identification?

Answer to Case 553

Answer to Parasite Case of the Week 553: Ascaris lumbricoides

The overall appearance and large size of this nematode are strongly suggestive of A. lumbricoides, given that this is a human stool specimen. As Sam mentioned, examining the anterior end for the characteristic 3 fleshy lips common to all ascarids, and examination of the stool for eggs would allow for confirmation of the identification.

Here are some images from other cases to show these characteristic features:
Adult with 3 fleshy lips from Case of the Week 479:

Mammillated and decorticated eggs from Case of the Week 550

Thanks to all that wrote in with the answer, and to Dr. Poloni for donating this case!

Case of the Week 552

This week's case is from Blaine Mathison. The following were seen on a trichrome-stained stool specimen. They averaged 5 to 7 micrometers in greatest dimension. A Giardia antigen test was positive.

Identification?