Monday, June 10, 2019

Case of the Week 548

This week's case was generously donated by Dr. Tara Ness, with filming credit to the Lab Hlathi Team in eSwatini. The following arthropod was found in the urine specimen of a man with HIV and a history of dysuria. Identification?



16 comments:

Sandeep Saluja said...

phthirus pubis

Dwight Ferris said...

Scabies = Sarcoptes scabiei

Unknown said...

I'm with Dwight: Sarcoptes scabei

Richard Pollack said...

Dermatophagoides? Possible contaminant in urine sample jar? If alive, it wouldn't have derived from the patient.

Anonymous said...

The morphology is microscopically compatible with dust mites Dermatophagoides spp. There may not be any pathologic link to the patient urinary condition, most probably an incidental finding in a non sterile collecting container as the mite is still alive.
Florida Fan

Idzi P. said...

I’m inclined to agree with Richard and Florida Fan: it’s a mite, but probably just a contaminant.

Gareth Weaver said...

Definitely not scabies. Could be dust mite - not considered a pathogen but the patient is immunocompromised......

Old One said...

It looks like the images were captured by cell phone. BRILLIANT. Very resourceful but lacking in detail. Superficially similar to Dermatophagoides sp ( a dust mite species) which has been found in human urine. But we are lacking morphological features to make an accurate identification. Dust mites are ubiquitous so contamination could be an issue. Rechecks would be in order.

Storage mites as well as dust mites find there way into human urinary systems. Are they pathogenic? I have no idea. They can elicit an eosinophilic response and because mites are known as burrowers they have been treated. Perhaps someone with more knowledge could comment on this topic.

Eagleville said...

Definitely looks more like a mite - not Phthirus pubis.

Old One said...

Our lab was most definitely a Veterinary Parasitology lab, but we did have occasional human visitors. Generally they were some of our most interesting visits.

A very fragile looking elderly lady showed up at our doorstep sitting in a wheel chair. She had managed the city bus service to get to campus, and managed our hilly campus with her hand-powered chair. Amazing as this was, she proceeded with an even more amazing story.

“I believe I have mites in my urine.”

I must tell you that I was “default guy” for these types of cases because I was the only one who would take the time to look into them. I guess word gets around.

Fortunately she was catheterized, so without haste I ran a number of sedimentations on her urine. I found nothing.

I asked if I could talk with her medical caretaker to discuss the results. The next day I was on the phone with her nurse, telling her that mites were a possibility but not very probable. Her sincere commitment to the thought she had urinary tract mites led me to think it might be a case of Delusional Parasitosis.

I’m hoping Dr. Pritt may have some wisdom to share on this topic.

Wan Hafiz said...

I think it is an adult house dust mite. Dermatophagoides sp.
I would be more sure if I could see any suckers at the end of the legs.
Contaminated urine sample.

Wan Hafiz

Blaine A. Mathison said...

Conta-mite-nt

Bernardino Rocha said...

Agree with dust mite (commensal). It's difficult to tell the genus, probably Dermatophagoides spp.

Sir Galahad said...

I agree :
Dermatophagoides farinae or Dermatophagoides pteronyssinus

Lilyana said...

Amazing post with lots of informative and useful and amazing content. Well written and done!! Thanks for sharing keep posting.

ParasiteGal said...

I forgot to respond to Old One (my apologies!) regarding my insights into mites in urine. In my experience, they have always been likely contaminants introduced into the staining or preparation process. Dust mites, in particular, are ubiquitous and therefore likely to get into just about everything. I have seen a similar mite in stool that mite have also represented a contaminant; however, I suppose it could have also been swallowed and passed through the GI tract! (think cheese mites, for example...) However, I think it wouldn't have been in such good shape as I saw it - so again, a likely contaminant. Sadly, delusional parasitosis is very commonly encountered in our field, and all the lab can do is accurately differentiate the true parasites from the free-living organisms and non-human parasites (plus all of the other 'stuff' that may resemble parasites but isn't). I feel badly for the poor patients that suffer from this disorder, and the physicians that do their best to help them. Thank you Old One for your interesting comments and antedotes!