A patient with HIV and a CD4 count of 50 cells/mm3 has a headache, and cerebrospinal fluid shows encapsulated yeast with India ink staining. Which organism is responsible?
Answer and explanation
Correct answer: A. Cryptococcus neoformans
- Step 1: Encapsulated yeast with a clear halo on India ink is Cryptococcus. Step 2. It causes meningitis in patients with low CD4 counts. Answer: Cryptococcus neoformans. Why not the others: Histoplasma is intracellular, Candida forms pseudohyphae and Aspergillus has septate hyphae with acute-angle branching.
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