Whilst the organism Pneumocystis carinii is now referred to as Pneumocystis jiroveci, the term

Pneumocystis carinii pneumonia (PCP) is still in common use

• Pneumocystis jiroveci is an unicellular eukaryote, generally classified as a fungus but some authorities consider it a protozoa
• PCP is the most common opportunistic infection in AIDS
• all patients with a CD4 count < 200/mm³ should receive PCP prophylaxis

PC

• dyspnoea
• dry cough
• fever
• very few chest signs - Scattered crackles and no focal consolidation is typical of PCP pneumonia.

Investigation

Bedside tests

• exercise-induced desaturation

Labs:

• sputum often fails to show PCP, bronchoalveolar lavage (BAL) often needed to demonstrate PCP (silver stain shows characteristic cysts)

Imaging:

• CXR: typically shows bilateral interstitial pulmonary infiltrates but can present with other x-ray findings e.g. lobar consolidation. May be normal
• CT