Mycology – Pneumocystis jirovecii pneumonia (PJP) Detection
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Background
This page provides direct microscopy testing information for Pneumocystis jirovecii, causative agent of Pneumocystis jirovecii pneumonia (PJP) at Public Health Ontario (PHO).
This page is for information specific to Pneumocystic jiroveci pneumonia (PJP) microscopy. For information regarding other testing options, refer to the following PHO webpages:
- Mycology – Fungal Culture – Superficial/Dermatophytes
- Mycology – Nocardia and Aerobic Actinomycetes Culture
- Mycology – Reference Identification of Yeast, Filamentous Fungi and Nocardia/Aerobic Actinomycetes
- Mycology – Susceptibility Testing of Yeast and Filamentous Fungi
- Mycology – Susceptibility Testing of Nocardia and Aerobic Actinomycetes
Updates
- The acceptance criteria for testing have been recently updated. Refer to the Acceptance/Rejection Criteria and Specimen Requirement sections of this test information sheet for details.
- The turnaround time has also been revised. Refer to the Test Frequency and Turnaround Time section of this test information sheet for the updated information.
Testing Indications
Patients suspected of having Pneumocystis jirovecii pneumonia.
Acceptance/Rejection Criteria
- Requests for testing will only be accepted for hospitalized patients (in-patients) who are immunocompromised with risk factors and clinical symptoms suggestive of PJP infection; this information must be indicated on the requisition. Absence of such information in the requisition will lead to rejection of the specimen for this testing.
- Only one specimen per patient per week will be tested. Pooled specimens will be accepted.
- Specimens collected using swab are not acceptable for testing.
- Expectorated sputum specimens are not acceptable for testing.
- If specimen does not meet the above acceptance criteria but testing is still warranted, contact PHO Laboratory Customer Service Centre at 1-877-604-4567 to seek approval from the Microbiologist overseeing Mycology.
Specimen Requirements
| Test Requested | Required Requisition(s) | Specimen Type | Minimum Volume | Collection Kit |
Pneumocystis jirovecii microscopy |
Respiratory specimens including: - bronchial washings |
1.0 mL |
Sterile container |
Submission and Collection Notes
Complete all fields of the requisition form, fields a-e are mandatory.
- Test(s) requests and indications for testing
- Specimen source (with details)
- Collection date and time
- Patient setting (eg. out-patient, in-patient, ICU, etc) - VERY important to note on the requisition
- Immune status – VERY important to note on the requisition if patient has had a transplant, has a haematological malignancy, or is otherwise immunocompromised (diabetes, etc). Absence of such information will lead to rejection of the specimen for testing. Refer to the Acceptance/Rejection Criteria.
For clinical specimens, label the specimen container(s) with the patient’s first and last name, date of collection, and one other unique identifier such as the patient’s date of birth or Health Card Number. For additional information see: Criteria for Acceptance of Patient Specimens. Failure to provide this information may result in rejection or testing delay.
Submit a separate specimen and requisition for mycology testing, no matter what additional testing is requested, i.e. if fungal culture and TB or Legionella culture are required, separate specimens and requisitions should be submitted for each.
Requests for both fungal culture and Pneumocystis jirovecii microscopy may be submitted using the same specimen and requisition.
Limitations
Fungi-fluor microscopy only allows for visualization of the cyst form.
Storage and Transport
Specimens should be stored at 2- 8 °C following collection and shipped to PHO’s Toronto laboratory with ice pack as soon as possible. All clinical specimens must be shipped in accordance to the Transportation of Dangerous Good Act.
Test Frequency and Turnaround Time (TAT)
Pneumocytis jirovecii microscopy is performed daily, Monday to Friday at PHO’s Toronto laboratory.
Turnaround time is up to 72 hours from receipt at PHO’s Toronto laboratory.
Specimens collected on Fridays, weekends and holidays, will be tested on next available business day.
STAT and Critical Specimens Testing
STAT testing available Monday-Friday if received at PHO’s Toronto laboratory by 14:00 EDT/EST.
STAT testing requests must be communicated in advance to the PHO Laboratory Customer Service Centre by calling 1-877-604-4567 prior to specimen submission.
Pneumocystis jirovecii microscopy (fluorescent) is performed on smears prepared from specimens that are stained by Fungi-fluor® Kit.
During the microscopic examination, fluorescing Pneumocystis jirovecii cysts are visually detected. The Fungi-fluor® Kit is a non-specific stain used for the rapid detection of fungal elements from clinical specimens by fluorescent microscopy.
Negative microscopy results do not necessarily rule-out the possibility of Pneumocystis jirovecii infection.
Interpretation
The following table provides possible test results with associated interpretations:
|
Microscopic Result |
Interpretation |
Comments |
|---|---|---|
|
Detected |
Cysts of Pneumocystis jirovecii seen |
None. |
|
Not detected |
No cysts of Pneumocystis jirovecii seen. |
A negative result does not rule out the presence of Pneumocystis jirovecii or active disease as the organism may be present at undetectable levels in this specimen. Consider resubmitting a new specimen if clinically indicated. |
|
Inconclusive |
Test results unable to determine presence/absence of Pneumocystis jirovecii cysts. |
The test will be repeated internally, if enough specimen remains, prior to issuing a report. Final report may indicate to resubmit specimen. |
Reporting
Results are reported to the physician, authorized health care provider (General O. Reg 45/22, s.18) or submitter as indicated on the requisition.
References
- Clinical and Laboratory Standards Institute (CLSI). Principles and Procedures for Detection and Culture of Fungi in Clinical Specimens. 2nd ed. CLSI guideline M54 (ISBN 978-1-68440-098-0 {Print}; ISBN 978-1-68440-099-7 {Electronic}). Clinical and Laboratory Standards Institute; 2021
- Hazen, K., Howell, S.A.. Mycology and antifungal susceptibility testing. In: Leber, A.M. Editor. Clinical Microbiology Procedures Handbook. 4th ed. Washington, D.C.; ASM Press; 2016.
- de Hoog, G.S., Guarro, J., Gene, J., Ahmed, S.A., Al-Hatmi, A.M.S., Figueras, M.J., Vitale, R.G.. Atlas of Clinical Fungi. 4th ed. Hilversum; Foundation Atlas of Clinical Fungi; 2020.
- Fungi-Fluor Kit Technical Data Sheet #482. Polysciences Inc.
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