Pneumonia USMLE Step 1 Practice Question
A 32-year-old immunocompromised man with CD4 count of 45 cells/μL presents with progressive dyspnea, fever, and dry cough for 2 weeks. Vital signs show temperature 38.5°C, HR 108 bpm, RR 28/min, BP 118/76 mmHg, and SpO2 88% on room air. Chest X-ray demonstrates bilateral interstitial infiltrates with ground-glass opacification. Lactate dehydrogenase is markedly elevated at 580 U/L. Sputum cultures remain negative. Which organism is most likely responsible?
Answer choices
- ACytomegalovirus pneumonitis
- BCandida albicans pneumonia
- CCryptococcal pneumonia
- DPneumocystis jirovecii pneumoniaCorrect answer
- EMycobacterium tuberculosis pneumonia
- FAspergillus fumigatus invasive pulmonary disease
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