infectious diseases
Cystoisosporiasis
Diagnosis of Cystoisosporiasis
Microscopic examination of stool Diagnosis of cystoisosporiasis is by detection of oocysts via microscopic examination of the stool. A modified Ziehl-Neelsen or Kinyoun acid-fast staining technique can help identifyCystoisosporaoocysts. Oocysts ofCystoisosporaare autofluorescent.Cystoisosporaoocysts are larger thanCyclosporaandCryptosporidiumoocysts, are ellipsoidal, and may contain one or two sporoblasts. Multiple (≥ 3) stool specimens may be needed because cyst secretion may be intermittent. Diagnosis is sometimes made only when intracellular parasite stages are detected in biopsies of intestinal tissue. In cystoisosporiasis, the stool may contain Charcot-Leyden crystals (hexagonal, double-pointed, and often needlelike crystals) derived from eosinophils. Cystoisosporiasis may result in peripheral blood eosinophilia. 