Monday, May 6, 2019

Case of the Week 543

This week we are featuring our monthly case from Idzi Potters and the Institute of Tropical Medicine, Antwerp.

The patient is a 15 year old boy returning from swimming camp, who presents with several-day history of profuse watery diarrhea. A stool specimen was submitted for parasite examination, and multiple small (3-6 µm), round structures were identified. The following photos are taken after:

1. Negative fuchsine staining according to Heine (brightfield microscopy)
2. Negative fuchsine staining according to Heine (phase-contrast microscopy)

3. Ziehl-Neelsen staining (“cold” modified technique)
Identification?

9 comments:

Sir Galahad said...


Cryptosporidium spp., oocisti.

Marta MP said...

Cryptosporidium oocyst

Hisar fan said...

Cryptosporidium

Anonymous said...

The negative stain is pretty cool Idzi, the oocysts stand out clearly against the background. From the previous comments, we clearly see that everyone called them Cryptosporidium spp. and not parvum since more than one species of Cryptosporidium can cause diarrhea to humans. Certainly the Direct Fluorescent Antibody does have its clinical value but when a suspected case does not fluoresce we need to confirm with the acid fast stain. Even so, we must keep in mind the truth that coccidian oocysts stain variably acid fast and some may appear as an empty hole with a ground glass interior.
Florida Fan

Sandeep Saluja said...

Cryptosporidium

Old One said...

Back in the day when I was still a wee baby, I came down with a severe case of watery diarrhea that couldn't be diagnosed or stopped. My parents and physician thought I was a goner but I managed to stick around. Fast forward to my years as a diagnostician, I was exposed to innumerable oocysts of Cryptosporidium spp. over 30 years, but never became infected. Did I acquire immunity from a past exposure?

Anonymous said...

Cryptosporidium spp based on the morphology and size on modified ZN staining. I cannot identify it at phase contrast microscope

watrouny said...

Agree Crypto. So there is only one in the first photo, three in the second (round white circles)?

Unknown said...

Oocytes of Cryptosporidium species based on Cold ZN