Pneumocystis carinii pneumonia (PCP) is a severe lung infection primarily caused by an opportunistic fungal pathogen called Pneumocystis jirovecii (formerly known as Pneumocystis carinii). This type of pneumonia commonly affects individuals with weakened immune systems, such as those living with HIV/AIDS, organ transplant recipients, or individuals undergoing cancer treatments.
PCP is characterized by the inflammation and swelling of the tiny air sacs (alveoli) present in the lungs, making it difficult for the affected person to breathe. Symptoms of PCP may include a dry cough, shortness of breath, fever, fatigue, and unintentional weight loss.
Pneumocystis jirovecii, the causative agent, is found ubiquitously in the environment and is transmitted primarily through inhalation of the fungal spores. However, most healthy individuals with a functioning immune system can effectively control the infection without showing signs or symptoms.
Diagnosing PCP usually involves examining respiratory samples, such as sputum or bronchoalveolar lavage fluid, under a microscope to detect the characteristic fungi. Treatment of PCP typically involves the administration of specific antimicrobial drugs, primarily trimethoprim-sulfamethoxazole (TMP-SMX). In severe cases or for individuals who cannot tolerate the primary treatment, alternative medications such as pentamidine or atovaquone may be prescribed.
Without appropriate treatment, PCP can be life-threatening, especially in individuals with compromised immunity. However, with early diagnosis and proper therapy, the prognosis for PCP patients is generally favorable.
