Case #143 - November, 2004
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.
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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