Fungal – Serology

Specimen Collection and Handling

Specimen Requirements

Test Requested Required Requisition(s) Specimen Type Minimum Volume Collection Kit

Fungal serology

Blood or serum

5.0 ml blood or 1.0 ml serum

Blood, clotted - vacutainer tubes (SST)

Submission and Collection Notes

1

Complete the following fields of the General Test Requisition Form if diagnostic testing is required:

  • Symptoms 
  • Onset date

Timing of Specimen Collection

An acute serum (collected early after the onset of symptoms) and a convalescent (collected 2-3 weeks later) may be required for laboratory diagnosis. Please see “Limitations of the Procedure” below, under Additional Information.

Limitations

Haemolysed, icteric, lipemic or microbially contaminated sera or plasma are not recommended for testing.

Preparation Prior to Transport

Label the specimen container with the patient’s full name, date of collection and one other unique identifier such as the patient’s date of birth or Health Card Number. Failure to provide this information may result in rejection or testing delay.

Special Instructions

Centrifuge if using SST. Place specimen in biohazard bag and seal.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

Fungal Immunodiffusion and Complement Fixation testing is performed once per week.

Turnaround time is up to 10 days from receipt by PHO Laboratory.

Reporting

Results are reported to the ordering physician or health care provider as indicated on the requisition.

Test Methods

Complement fixation (CF) test is performed for the detection of antibodies to Histoplasma capsulatum, Blastomyces dermatitidis and Coccidioides immitis. A positive serologic response may take more than 4 weeks to develop. Sensitivity is poor for blastomycosis, 70-90% at 6 weeks post-infection for histoplasmosis and up to 90% for coccidioidomycosis. Cross-reactions among these three fungi may occur, reducing the specificity of the tests

Immunodiffusion (ID) test is performed for the detection of antibodies to H. capsulatum, B. dermatitidis, C. immitis and Aspergillus species

Aspergillus ID test: Demonstration of one or more precipitin bands against Aspergillus antigen is presumptive evidence of colonization or allergy to an Aspergillus species. This test may be useful in the diagnosis of allergic bronchopulmonary aspergillosis, but is not helpful in the diagnosis of invasive aspergillosis.

B. dermatitidis ID test:  A positive test (A band) provides presumptive evidence of infection.  A negative test does not exclude the existence of active blastomycosis.

C. immitis ID test: A positive test (F band) is presumptive evidence of C. immitis infection.  A negative test does not exclude coccidioidomycosis.

H. capsulatum ID test: A positive test (H and/or M band) provides presumptive evidence of infection. H band is indicative of acute infection, whereas M band is positive in prior infections, and both acute and chronic disease. A negative test does not exclude the existence of histoplasmosis. 

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Laboratory Services

customerservicecentre@oahpp.ca

Updated 19 June 2019