Pneumocystis Pneumonia (PCP)

Pneumocystis pneumonia (PCP) is a serious lung infection caused by the fungus Pneumocystis jirovecii, occurring almost exclusively in people with significantly weakened immunity, most commonly advanced, untreated HIV infection.

• Gradual onset, over days to weeks, of dry cough and progressively worsening shortness of breath, particularly on exertion
• Fever
• Chest tightness
• Symptoms often seem out of proportion to relatively subtle findings on chest examination, which is a characteristic feature of this infection

• Caused by the fungus Pneumocystis jirovecii.
• Occurs almost exclusively in people with significantly weakened immunity, most commonly advanced, untreated HIV infection with a very low CD4 count.

• Suspected in anyone with advanced or untreated HIV infection presenting with gradually worsening cough and breathlessness, especially when chest examination findings seem mild compared to the degree of breathlessness.
• Chest X-ray often shows characteristic widespread lung changes, though it can occasionally appear normal early in the illness.
• Pulse oximetry, where available, is useful to assess the severity of low blood oxygen, which is often more pronounced than clinical examination alone suggests.
• Sputum testing for the organism may be available at referral level to confirm the diagnosis.

High-dose cotrimoxazole is the treatment of choice, given for a course of about three weeks, adjusted for kidney function and monitored for side effects.

Oxygen therapy is given for low blood oxygen, and severe cases with significant hypoxia require hospital admission.

A corticosteroid is added early in moderate to severe cases with significant hypoxia, as it improves outcomes by reducing lung inflammation.

Antiretroviral therapy for HIV is typically started within about two weeks of beginning PCP treatment, following national guidance.

After treatment of the acute episode, secondary prophylaxis with cotrimoxazole is continued until the immune system has recovered sufficiently on antiretroviral therapy.

• Early HIV diagnosis and prompt antiretroviral therapy prevent the severe immune suppression that allows PCP to occur.
• Cotrimoxazole preventive therapy is given to people with HIV and a low CD4 count (or other qualifying criteria) to prevent a first episode of PCP and other infections.
• Seek prompt medical assessment for new or worsening cough and breathlessness in anyone with known advanced or untreated HIV infection.