HIV – PCR

Testing Indications

HIV PCR testing has been authorized by Health Canada on Clinical Trial Status (CTS). Under CTS, designated labs may use PCR to assist in the diagnosis of HIV under specific conditions:

  • Diagnosis of HIV in infants born to HIV positive mothers
  • The resolution of HIV antibody indeterminate cases
  • The diagnosis of HIV infection in individuals likely to be in a pre-antibody, sero-conversion window                                                                 
  • Other circumstances after discussion with PHOL; contact PHOL Customer Service Centre

Specimen Collection and Handling

Specimen Requirements

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

HIV 1 PCR

Whole blood submitted in EDTA1,2

400 μl (HIV PCR testing) or 2000 μl (if requesting HIV antibody and PCR testing on the same sample)

Lavender topped-EDTA tube

HIV 1 PCR

Plasma4

1100 μl (HIV PCR testing) or 3000 μl (if requesting HIV antibody and PCR testing on the sample sample)

Lavender topped-EDTA tube

HIV 1 PCR

Dried Blood Spot (DBS)5,6

4 DBS per patient sample

Dried blood spot card5,6

HIV 2 PCR

EDTA whole blood3

5000 μl

Lavender topped-EDTA tube

Submission and Collection Notes

1

For infants < 18 months, check the box located in ‘Specimen Details’ beside HIV PCR (for infant diagnosis < 18 mos)

2

For HIV 1 PCR: For whole blood submitted in EDTA – send specimen to PHO laboratory on icepacks ASAP after collection. Whole blood must be received at PHO laboratory within 5 days after collection.

3

For HIV 2 PCR: For whole blood submitted in EDTA – keep specimen at room temperature and send specimen ASAP to PHO laboratory. Specimen must be received at the National Laboratory HIV Reference Services (NLHRS) in Winnipeg within 48 hours of collection.

4

For HIV 1 PCR: Separate plasma from whole blood within 24 hours of collection. After plasma separation, plasma can be stored at 25 to 30°C for one day; at 2 to 8°C for up to five (5) days; or at -20 to -80°C for 6 weeks.

5

Filter cards containing dried blood spots should be shipped to PHO laboratory in individual sealable bags containing a desiccant sachet. When sample is appropriately prepared, it will be stable at room temperature for 30 days. Do not refrigerate samples.

6

PHO laboratory does not provide DBS cards. Refer to LAB-SD-086 for suggested suppliers.

Limitations

  1. Yellow topped ACD tubes or Green topped Heparin tubes are not acceptable. See Specimen Collection and Handling section for acceptable collection tubes.
  2. Specimen integrity is of critical importance as contaminated specimens may cause a false positive reaction in the assay and older specimens may degrade to falsely negative results.
  3. Some divergent genetic variants of HIV may not be successfully amplified and detected by the current assay.

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.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

HIV 1 PCR turnaround time is up to 10 days from receipt by PHO laboratory. Testing is performed twice a week.

Specimens for HIV 2 PCR are Referred to National Laboratory HIV Reference Services (NLHRS) in Winnipeg. Turnaround time is up to 14 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

HIV 1 PCR testing is performed using a qualitative Nucleic Acid Amplification assay (based on PCR). It is a molecular technique which amplifies and detects specific HIV 1 RNA and proviral DNA in plasma, anti-coagulated whole blood and dried blood spots.

For HIV 2 PCR test method, contact NLHRS for further information:

Phone: (204)789-6523
Email: phac.nlhrs-lnsrv.aspc@canada.ca

The HIV 1/2 PCR test is only considered useful when considered together with other licensed serological markers such as HIV1/2 antigen/antibody combo screen and HIV 1/2 Differential assay. 

contact lab

Contact Laboratory Customer Service

Laboratory Services

customerservicecentre@oahpp.ca

Updated 15 April 2019