USMLE PRACTICE QUESTION OF THE WEEK

Question for March 13, 2026

A 44-year-old man with HIV presents with worsening cough, weight loss, and fever. He is nonadherent with antiretroviral therapy. CD4 count is 38/µL. Chest x-ray shows diffuse interstitial infiltrates. Bronchoalveolar lavage reveals organisms that stain with methenamine silver and appear as cup-shaped cysts.

Which of the following is the most appropriate initial therapy?

A. Azithromycin

B. Fluconazole

C. Ganciclovir

D. TMP-SMX

E. Voriconazole

Get Detailed Explanation

Correct Answer:

D. TMP-SMX

Correct Answer Explanation:

This patient has Pneumocystis jirovecii pneumonia, common in HIV patients with CD4 <200. TMP-SMX is first-line treatment. Azithromycin is for Mycoplasma. Fluconazole treats cryptococcosis. Ganciclovir treats CMV.

Further Insight:

Add corticosteroids if PaO₂ <70 mm Hg or A–a gradient >35 mmHg.
Prophylaxis with TMP-SMX indicated when CD4 <200.