The histological description—small, curved, flagellated organisms in the duodenal mucus layer without attachment or invasion—is characteristic of the trophozoites of the non-pathogenic commensal flagellate, Chilomastix mesnili. This parasite is often an incidental finding. In an immunocompetent host, it would be dismissed. However, in this HIV-positive patient with low CD4 count and chronic diarrhea, its significance is unclear. It is unlikely to be the primary cause of diarrhea, as it is non-invasive and does not attach. The key point is that standard stool O&P exams are often negative for C. mesnili because: 1) Its trophozoites are fragile and disintegrate quickly in stool, especially if not examined immediately. 2) Cyst shedding may be intermittent. The biopsy provides a direct view of the duodenal contents. The patient's diarrhea is more likely due to other opportunistic infections (like Microsporidia or Mycobacterium avium complex) or HIV enteropathy. Finding C. mesnili is likely coincidental. The other options are incorrect: Giardia attaches via a sucking disc. Strongyloides would show larvae, not flagellates. Dientamoeba is an amoeba, not a flagellate.

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Zambia

• loveness Phiri – 1084 pts

• Visual Pathway Lesions
• Positive and Negative Symptoms
• Hallucinations and Delusions
• Antipsychotic Medications
• Emergency: Environmental Emergencies