Preferred test for detection of Pneumocystis
Sources: Bronchoalveolar lavage, bronchial washing, tracheal secretions, or sputum
NALC/NaOH-digested respiratory specimens
Sources: Lavage fluid, bronchial washing, respiratory fluid, sputum, or tracheal secretion
Specimen must arrive within 7 days of collection; specimens older than 7 days will be rejected.
Specimen Required: The high sensitivity of amplification by PCR requires the specimen to be processed in an environment in which contamination of the specimen by Pneumocystis species DNA is unlikely.
Necessary Information: Specimen source is required.
Specimen Type: Tissue:
1. Submit fresh tissue.
2. Keep tissue moist with sterile water or sterile saline
Body fluid other than pleural fluid, blood, bone, nonrespiratory tissue, bone marrow, organ tissues other than lung, paraffin-embedded tissue Specimen in anaerobe vial or viral transport medium Feces Swab Tissue in formalin fluid Urine Specimen >7 days old.
Test results should be used as an aid in diagnosis and should not be considered diagnostic in themselves. The literature indicates that Pneumocystis can cause asymptomatic colonization of healthy and immunocompromised individuals. Therefore, test results should be correlated with patient symptoms and clinical presentation.
A negative result does not rule out the presence of Pneumocystis or active disease because the organism may be present at undetectable levels.
Pneumocystis pneumonia is an important cause of opportunistic infection in immunocompromised patients, particularly those with HIV. The causative agent, Pneumocystis jiroveci, cannot be cultured in vitro and, therefore, laboratory detection has historically relied upon microscopic identification directly from patient specimens using fluorescent stains or antibodies. Unfortunately, stains often lack sensitivity and require expertise on the part of the reader in order to differentiate Pneumocystis jiroveci from staining artifacts and other fungi. This real-time PCR assay provides sensitive (21% more sensitive than direct detection using fluorescent calcofluor white stain), specific, and objective detection of Pneumocystis from bronchoalveolar lavage fluid and other specimens.
A positive result indicates the presence of Pneumocystis DNA.
A negative result indicates the absence of detectable Pneumocystis DNA.