Opportunistic Pneumonia
Impaired immunity leaves patients vulnerable to serious, life-threatening pneumonias known as opportunistic pneumonias. They are caused by organisms that are harmless to people with healthy immune systems. Infecting organisms include:
- Pneumocystis carinii, renamed Pneumocystis jiroveci in 2002, is an atypical organism. Originally thought to be protozoa, it is now classified as a fungus. P. jiroveci is very common and generally harmless in people with healthy immune systems. It is the most common cause of pneumonia in AIDS patients.
- Mycobacteria avium complex
- Viruses, such as cytomegalovirus (CMV)
- Fungi, such as Candida albicans
|
Click the icon to see an image of CMV. |
In addition to AIDS, other conditions put patients at risk for opportunistic pneumonia. They include cancers, such as lymphoma and leukemia. Long-term use of corticosteroids and drugs known as immunosuppressants also increases the risk for these pneumonias.
Occupational and Regional Pneumonias
Exposure to chemicals can also cause inflammation and pneumonia. Where you work and live can put you at higher risk for exposure to pneumonia-causing organisms.
- Workers exposed to cattle, pigs, sheep, and horses are at risk for pneumonia caused by anthrax, brucella, and Coxiella burnetii (which causes Q fever).
|
Click the icon to see an image of inhalation anthrax. |
Previous Section
Review Date: 04/13/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine,
Harvard Medical School; Physician, Massachusetts General Hospital.
Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M.,
Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
