Case #143 - November, 2004
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Answer to Case #143
This case showed a mixed infection of both microsporidiosis and cryptosporidiosis (initially suspected in the Chromotrope 2R stained smear). Diagnostic morphologic features of microsporidian spores that were observed in all three images included:
- small, oval spores measuring approximately 1-2 micrometers with a pinkish red color after staining with Chromotrope 2R stain (arrow, Figure A).
- presence of an equatorial band or belt-like stripe on some of the spores, consistent with spores of microsporidia.
In Figures A and C, oocysts of Cryptosporidium could also be identified. Morphologic features observed were:
- round, cyst-like objects approximately 5 micrometers in diameter, very suggestive of Cryptosporidium oocysts.
Since the Chromotrope 2R stain is not a standard stain used for identification of Cryptosporidium, a confirmatory test such as an acid-fast stained smear or DFA test for Cryptosporidium should be utilized. Image D below shows the objects seen on the modified Kinyoun’s acid-fast stained smear, confirming the presence of Cryptosporidium oocysts.
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More on: Microsporidiosis: Cryptosporidiosis
Images presented in the monthly case studies are from specimens submitted for diagnosis or archiving. On rare occasions, clinical histories given may be partly fictitious.
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