Pneumonia is a lung infection that can be caused by many different germs, including bacteria, viruses, and fungi.
This article discusses pneumonia that occurs in a person whose ability to fight infection is greatly reduced because their immune system is weakened and not working properly. Such disease is referred to as “pneumonia in an immunocompromised host.”
Pneumocystis jirovecii (previously called Pneumocystis carinii) pneumonia
Pneumonia – cytomegalovirus
Pneumonia in immunodeficient patient; Pneumonia – immunocompromised host
Causes, incidence, and risk factors
People whose immune system is not working well are less able to fight off germs. Because of this state, they are more likely to become infected by germs that typically do not cause disease in healthy people. They are also more vulnerable to the usual causes of
Your immune system may be weakened or not work well because of:
Bone marrow transplant
Leukemia, lymphoma, and other conditions that harm your bone marrow
Medications (including steroids, and those used to treat cancer and control autoimmune diseases)
Organ transplant (including kidney, heart, and lung)
- Cough (may be dry or produce mucus-like, greenish, or pus-like sputum)
- Chills with shaking
Easy fatigue Fever
- General discomfort, uneasiness, or ill feeling (
- Loss of appetite
- Nausea and vomiting
- Sharp or stabbing
chest painthat gets worse with deep breathing or coughing Shortness of breath
Other symptoms that may occur:
Excessive sweating or night sweats
Joint stiffness (rare)
Muscle stiffness (rare)
Signs and tests
The doctor may hear crackles or other abnormal breath sounds when listening to the chest with a stethoscope. Reduced or absent breath sounds can be an important sign, because it may mean there is a buildup of fluid between the chest wall and lung, called a
Tests may include:
Arterial blood gases
Bronchoscopy(in certain cases) Chest CT scan(in certain cases) Chest x-ray Complete blood count Lung biopsy(in certain cases)
- Serum Cryptococcus antigen test
Sputum Gram stain Sputum immunofluorescence tests(or other immune tests)
- Urine tests (to diagnose
Antibiotics or antifungal medicines are used, depending on the type of germ that is causing the infection. Patients usually must stay in the hospital, at least during the early stages of the illness.
The outcome may be poor if the pneumonia is caused by a virus or fungus, or if the patient’s immune system is severely weakened.
- Respiratory failure (the person needs machines to assist in breathing)
- Spread of the infection
Calling your health care provider
Call your health care provider if you have a weakened immune system and you have symptoms of pneumonia.
If you have a weakened immune system and are in the hospital, you may receive daily antibiotics to prevent pneumonia.
Ask your health care provider if you should receive the influenza (“flu”) and pneumococcal (“pneumonia”) vaccines.
Practice good hygiene. Thoroughly wash your hands with soap and water:
After being outdoors
After changing a diaper
After doing housework
After going to the bathroom
After touching body fluids, such as mucus or blood
After using the telephone
Before handling food or eating
Keep your house clean. Stay away from crowds. Ask visitors who have a cold to wear a mask or not to visit. Do not do yard work or handle plants or flowers (they can carry germs).