This week's case was generously donated by Florida Fan and is very appropriate for this time of the year!
The following objects were seen on a stool specimen that had been stained by Wright-Giemsa to look for fecal leukocytes (total magnification 1000x). Preliminary identification? What additional stain would you like to perform to confirm your diagnosis?
Cryptosporidium
ReplyDeleteDepending on the calibration of the micrometer; I'm thinking Cyclospora; 8-10 microns, and the crinkled internal appearance.
ReplyDeleteCyclospora cayetanensis oocysts
ReplyDeleteCyclospora oocysts
ReplyDeleteCoccidia....Crypto???? yet size is a concern....Cyclo is more circular than ovular but roughly matches the size of this picture (size of a red blood cell); Go for modified Kinyoun's ZN stain and measure the size. I will go with Cryptosporidium as preliminary diagnosis.
ReplyDeleteSize makes me lean towards Cyclospora. Cryptosporidium would be somewhat smaller. To be confirmed with modified Ziehl-Neelsen or other acid-fast staining technique. Or even better: check using autofluorescence! Cryptosporidium does NOT have this cool feature of autofluorescence while Cyclospora does!
ReplyDeleteI have no identification but I do have a question.
ReplyDeleteDo coccidian oocysts normally indent and deform in Wright-Giemsa?
Back in the dark ages, if I thought they were coccidia. I would put them in K dichromate and let them sporulate.
This is a cyclospora cayatenensis oocyst (8-10 micrometer). The patient may be asked to eat raspberries or basil recently. Modified acid fast staining of stool specimens is also recommended. Since Cyclospora oocysts give autofluorescence in a 380-420 nm filter, the stool sample can be examined under a fluorescent microscope.
ReplyDeleteI am tempted to accept Cyclospora cayetanensis as a diagnosis, but it´s a sporocyst (sporulated oocyst), given its shape. As noted, modified Ziehl-Neelsen and safranin stains techniques could be used.
ReplyDeleteLa terza foto sembra un granulo pollinico
ReplyDeleteAhhh Cyclospora, my favourite.
ReplyDeleteI would bet that there is an outbreak that has been multistate for several weeks (not announced and identified yet). Often CDC is unable to call an outbreak for several weeks after the index cases become clustered. Cyclospora has challenging biology that makes outbreak tracing very difficult for PHLs (sporulation in the environment for weeks after passage and transport of produce for thousands of miles from origin). We have seen clusters in NY, MD, KY, and TX in the last 3 weeks.
Acid fast
ReplyDelete