Pneumocystis Pneumonia (PCP): Introduction, Symptoms, Lab Diagnosis and Treatment
Introduction of Pneumocystis pneumonia (PCP)
Pneumocystis pneumonia is a serious fungal infection which the causative agent Pneumocystis jirovecii. PCP spreads from person to person through the air. Some healthy adults can carry the Pneumocystis fungus in their lungs without having symptoms, and it can spread to other people, including those with weakened immune systems like-
Inflammatory diseases or autoimmune diseases i.e. lupus or rheumatoid arthritis
Stem cell transplant.
Species: P. jirovecii
Binomial name: Pneumocystis jirovecii
Scientists have changed both the classification and the name of this organism since it first appeared in patients with HIV in the 1980s. Pneumocystis jirovecii used to be classified as a protozoan but is now considered a fungus (from 2001). Pneumocystis jirovecii used to be called Pneumocystis carinii. When scientists renamed Pneumocystis carinii to Pneumocystis jirovecii, some people considered using the abbreviation ‘PJP’, but to avoid confusion, Pneumocystis jirovecii pneumonia is still abbreviated ‘PCP.’
Sign and Symptom of Pneumocystis pneumonia
The sign and symptoms of PCP include-
Extrapulmonary Pneumocystis has also been reported in patients with
advanced HIV disease, particularly in the setting of aerosolized
pentamidine prophylaxis. Other organs affected are-
and lymph nodes.
Lab Diagnosis of Pneumocystis pneumonia
It includes bronchoalveolar lavage (BAL), transbronchial biopsy, sputum, and open lung biopsy. BAL and sputum should always be stained for acid-fast bacillus and other fungi also.
Staining methods for Pneumocystis jiroveci include:
Fluorescent antibody staining with monoclonal antibody: this is more specific and sometimes more sensitive when a low number of organisms is present in the specimen. polymerase chain reaction (PCR)
Note: The lifecycle of pneumocystis, is not clearly understood, contains at least two stages. One is the cyst and another trophozoite. The walls of the cyst forms take up the GMS and Toluidine Blue O stain round or cup or typically ‘deflated-ball’-shaped. Trophozoites and cysts are seen in Giemsa stain but cysts having up to eight sporozoites.
High serum LDH
Arterial blood gas analysis is very important in the management of cases.
High-resolution CT scan
Treatment of Pneumocystis pneumonia
The choice of drug used to prevent PCP is trimethoprim/sulfamethoxazole (TMP/SMX), which is also called co-trimoxazole. Its several different brand names are Cotrim, Bactrim, and, Septra.
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