Question

Pneumocystis jiroveci is:

• A. Associated with CMV
• B. Diagnosis is by sputum microscopy
• C. Seen only in immunocompromised patients
• D. Always associated with pneumatocele

Hint:

Think of the quick non-invasive first specimen used to demonstrate this alveolar pathogen.

Answer 1

The Correct Option is B

Step 1: Pneumocystis jiroveci is the human isolate of Pneumocystis, an extracellular pathogen that causes severe pneumonia in the immunocompromised, particularly in AIDS. Its growth in the lung is confined to the surfactant layer above the alveolar epithelium. Step 2: Diagnosis rests on detecting the organism in a proper specimen. Sputum microscopy is quick and non-invasive, bronchoalveolar lavage (BAL) fluid is the mainstay, and transbronchial biopsy is used if BAL fails, so option b is correct. Step 3: Serologic evidence shows most people are infected in early childhood, so the organism is not restricted to immunocompromised hosts; only the pneumonia is, which makes option c wrong. Step 4: It is not inherently linked to CMV, and pneumatoceles are not an invariable feature, ruling out options a and d.