This type of pneumonia is caused by the fungus Pneumocystis jiroveci. This fungus is common in the environment and rarely causes illness in healthy people.
However, it can cause a lung infection in people with a weakened immune system due to:
- Long-term use of corticosteroids or other medicines that weaken the immune system
- Organ or bone marrow transplant
Pneumocystis jiroveci was a rare infection before the AIDS epidemic. Before the use of preventive antibiotics for the condition, most people in the United States with advanced AIDS often developed this infection.
Pneumocystis jiroveci pneumonia is a fungal infection of the lungs. The disease used to be called Pneumocystis carini or PCP pneumonia.
Exams and Tests
Your health care provider will examine you and ask about your symptoms.
Tests that may be ordered include:
Pneumocystis pneumonia can be life threatening, causing respiratory failure that can lead to death. People with this condition need early and effective treatment. For moderate to severe pneumocystis pneumonia in people with HIV/AIDS, the short term use of corticosteroids has decreased the incidence of death.
Complications that may result include:
Preventive therapy is recommended for:
- People with HIV/AIDS who have CD4 counts below 200 cells/microliter or 200 cells/cubic millimeter
- Bone marrow transplant recipients
- Organ transplant recipients
- People who take long-term, high-dose corticosteroids
- People who have had previous episodes of this infection
- People who take long-term immunomodulatory drugs
Pneumocystis pneumonia in people with AIDS usually develops slowly over days to weeks or even months, and is less severe. People with pneumocystis pneumonia who do not have AIDS usually get sick faster and are more severely ill.
- Cough, often mild and dry
- Rapid breathing
- Shortness of breath, especially with activity (exertion)
Anti-infection medicines can be given by mouth (orally) or through a vein (intravenously), depending on how severe the illness is.
People with low oxygen levels and moderate to severe disease are often prescribed corticosteroids as well.
When to Contact a Medical Professional
If you have a weakened immune system due to AIDS, cancer, transplantation, or corticosteroid use, call your provider if you develop a cough, fever, or shortness of breath.
Kovacs JA. Pneumocystis pneumonia. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 341.
Walzer PD, Smulian AG, Miller RF. Pneumocystis species. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 271.