Pneumocystis jirovecii pneumonia
Pneumocystis pneumonia; Pneumocystosis; PCP; Pneumocystis carinii; PJP pneumoniaPneumocystis jirovecii pneumonia is a fungal infection of the lungs. The disease used to be called Pneumocystis carinii or PCP pneumonia.
Causes
This type of pneumonia is caused by the fungus Pneumocystis jirovecii. 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:
- Cancer
Cancer
Cancer is the uncontrolled growth of abnormal cells in the body. Cancerous cells are also called malignant cells.
Read Article Now Book Mark Article - Long-term use of corticosteroids or other medicines that weaken the immune system
- HIV/AIDS
HIV/AIDS
Human immunodeficiency virus (HIV) is the virus that causes acquired immunodeficiency syndrome (AIDS). When a person becomes infected with HIV, the ...
Read Article Now Book Mark Article - Organ or bone marrow transplantation
Bone marrow transplantation
A bone marrow transplant is a procedure to replace damaged or diseased bone marrow with healthy bone marrow stem cells. Bone marrow is the soft, fatt...
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Pneumocystis jirovecii 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 developed this infection.
Symptoms
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.
Symptoms include:
- Cough, often mild and dry
- Fever
- Rapid breathing
- Shortness of breath, especially with activity (exertion)
Exams and Tests
Your health care provider will examine you and ask about your symptoms.
Tests that may be ordered include:
- Blood gases (both arterial and venous)
Blood gases
Blood gases are a measurement of how much oxygen and carbon dioxide are in your blood. They also determine the acidity (pH) of your blood.
Read Article Now Book Mark Article - Bronchoscopy (with lavage)
Bronchoscopy
Bronchoscopy is a test to view the airways and diagnose lung disease. It may also be used during the treatment of some lung conditions.
Read Article Now Book Mark Article - Lung biopsy
Lung biopsy
A lung needle biopsy is a method to remove a piece of lung tissue for examination. If it is done through the wall of your chest, it is called a tran...
Read Article Now Book Mark Article - X-ray of the chest
X-ray of the chest
A chest x-ray is an x-ray of the chest, lungs, heart, large arteries, ribs, and diaphragm.
Read Article Now Book Mark Article - Sputum exam to check for fungus that causes the infection
Sputum exam
Routine sputum culture is a laboratory test that looks for germs that cause infection. Sputum is the material that comes up from air passages when y...
Read Article Now Book Mark Article - Complete blood count (CBC)
Complete blood count
A complete blood count (CBC) test measures the following:The number of white blood cells (WBC count)The number of red blood cells (RBC count)The numb...
Read Article Now Book Mark Article - Beta-1,3 glucan level in the blood and/or lavage fluid from bronchoscopy
Treatment
Anti-infection medicines can be given by mouth (orally) or through a vein (intravenously), depending on how severe the illness is.
Intravenously
Intravenous means "within a vein. " Most often it refers to giving medicines or fluids through a needle or tube inserted into a vein. This allows th...
Read Article Now Book Mark ArticlePeople with low oxygen levels and moderate to severe disease are often prescribed corticosteroids as well.
Outlook (Prognosis)
Pneumocystis pneumonia can be life threatening. It can cause 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.
Possible Complications
Complications that may result include:
- Pleural effusion (extremely rare)
Pleural effusion
A pleural effusion is a buildup of fluid between the layers of tissue that line the lungs and chest cavity.
Read Article Now Book Mark Article - Pneumothorax (collapsed lung)
Pneumothorax
A collapsed lung occurs when air escapes from the lung. The air then fills the space outside of the lung between the lung and chest wall. This buil...
Read Article Now Book Mark Article - Respiratory failure (may require breathing support)
Respiratory failure
Respiratory acidosis is a condition that occurs when your lungs can’t remove all of the carbon dioxide produced by your body. This causes the blood ...
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When to Contact a Medical Professional
If you have a weakened immune system due to AIDS, cancer, transplantation, or corticosteroid use, contact your provider if you develop a cough, fever, or shortness of breath.
Prevention
Preventive therapy is recommended for:
- People with HIV/AIDS who have CD4 counts below 200 cells/microliter or 200 cells/cubic millimeter
CD4 counts
Human immunodeficiency virus (HIV) is the virus that causes acquired immunodeficiency syndrome (AIDS). When a person becomes infected with HIV, the ...
Read Article Now Book Mark Article - 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 medicines
References
Kovacs JA. Pneumocystis pneumonia. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 313.
Miller RF Walzer PD, Smulian AG. Pneumocystis species. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 269.
Lungs - illustration
The major features of the lungs include the bronchi, the bronchioles and the alveoli. The alveoli are the microscopic blood vessel-lined sacks in which oxygen and carbon dioxide gas are exchanged.
Lungs
illustration
AIDS - illustration
AIDS (acquired immune deficiency syndrome) is caused by HIV (human immunodeficiency virus), and is a syndrome that leaves the body vulnerable to a host of life-threatening illnesses. There is no cure for AIDS, but treatment with antiviral medicine can suppress symptoms. AIDS is universally fatal, in large part due to the proliferation of opportunistic infections.
AIDS
illustration
Pneumocystosis - illustration
Pneumocystosis is an infection of the lungs caused by the microorganism Pneumocystis carinii. Pneumocystosis is almost exclusively seen in individuals whose immune systems have been compromised by AIDS or chemotherapy. Pneumocystosis is usually a terminal event in AIDS patients.
Pneumocystosis
illustration
Lungs - illustration
The major features of the lungs include the bronchi, the bronchioles and the alveoli. The alveoli are the microscopic blood vessel-lined sacks in which oxygen and carbon dioxide gas are exchanged.
Lungs
illustration
AIDS - illustration
AIDS (acquired immune deficiency syndrome) is caused by HIV (human immunodeficiency virus), and is a syndrome that leaves the body vulnerable to a host of life-threatening illnesses. There is no cure for AIDS, but treatment with antiviral medicine can suppress symptoms. AIDS is universally fatal, in large part due to the proliferation of opportunistic infections.
AIDS
illustration
Pneumocystosis - illustration
Pneumocystosis is an infection of the lungs caused by the microorganism Pneumocystis carinii. Pneumocystosis is almost exclusively seen in individuals whose immune systems have been compromised by AIDS or chemotherapy. Pneumocystosis is usually a terminal event in AIDS patients.
Pneumocystosis
illustration
Review Date: 12/31/2023
Reviewed By: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.