Pneumocystis carinii pneumonia
Alternative names:
pneumocystosis; pneumonia - pneumocystis carinii
Definition:
An infection of the lungs caused by the microorganism Pneumocystis
carinii.
Causes, incidence, and risk factors:
Pneumocystis carinii is found in the lungs of humans and
wild and domesticated animals. Typically, P. carinii is not
a pathogen (disease-causing organism) in healthy humans. In
people with weak immune systems, however, it can cause Pneumocystis
carinii pneumonia (PCP). Therefore, the disease is rare in
the general population, although asymptomatic
infections occur in many people early in life.
PCP primarily affects hospitalized premature infants, cancer
patients, patients being treated with immunosuppressive medications
for the management of organ transplantation or cancer, and
AIDS patients. Before
the AIDS epidemic, PCP was seldom seen. It is now recognized
with increased frequency in non-AIDS immunocompromised patients.
During the early years of the HIV epidemic, PCP occurred in
approximately 80% of AIDS patients. With the use of effective
antiretroviral therapy and PCP prophylaxis this percentage
is much lower now.
There are presently only a few effective chemotherapeutic
agents available against this infection: trimethoprim-sulfamethoxazole,
pentamidine, clindamycin plus primaquine, atovaquone, and
trimethoprim plus dapsone.
Research on the effectiveness of other drugs is presently
in progress.
In the older child and adult pneumocystis pneumonia
may begin suddenly with fever,
dry non-productive cough, rapid
breathing (tachypnea)
and a feeling of being short of breath. Oxygen is required
because the infection interferes with the exchange of gasses
across the lung membranes.
Update Date: 02/09/00
Updated by: J. Gordon Lambert, MD, Associate Medical Director,
Utah Health Informatics and adam.com
editorial
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