Mycology/Parasitology USMLE Step 1 Practice Question
A 45-year-old man with advanced HIV (CD4 count 38/μL) presents with severe headache, fever (39.2°C), and neck stiffness. Vital signs show BP 118/76, HR 94, RR 18, SpO2 98% on room air. CSF analysis reveals elevated protein (120 mg/dL), low glucose (28 mg/dL), and India ink stain positive for encapsulated yeast. Blood cultures remain negative. He denies photophobia. Which additional CSF finding would most confirm this diagnosis?
Answer choices
- ACoccidioidal serology with IgG antibodies
- BAspergillus PCR in blood
- CPositive serum and CSF cryptococcal antigenCorrect answer
- DEndospores visible on wet mount
- EPositive AFB smear on sputum
- FNegative bacterial and fungal blood cultures with positive Gram stain of CSF showing gram-positive cocci
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