Test Guide Mobile

Human Immunodeficiency Virus Viral Load
Also known as : [HIV Viral Load]

Blood
Test performed by: LabPLUS VIM Molecular Diagnostics

Relevant clinical details MUST be written on the request form otherwise the test will be declined .

Specimens from the following clinical areas/situations will be accepted:

Infectious Diseases
Sexual Health
Confirmation of HIV infection in a patient with a reactive HIV screening test (HIV Ab/Ag+)
Viral load monitoring in a patient with known HIV
Child at risk of vertical HIV transmission from mother with known HIV
Clinical suspicion of acute HIV prior to seroconversion
Bone marrow transplant (BMT) donor screening
Other clinical details which justify HIV Viral Load testing

A dedicated specimen (i.e. no other tests to be performed) is required for this assay.

Do not use heparin tubes

Do not use serum.

Viral load results may be adversely affected by delay in transport.

Specimen Collection
5 mL PPT Plasma (Preferred)
The absolute minimum volume required for the test is 2.5 mL
Do not freeze unseparated PPT tubes . If the specimen requires freezing, the supernatant must be removed from the gel first.
Require dedicated PPT specimen (no other tests requested).
Transport at 2 - 8 degrees C if transport time from collection is less than 5 days.

Specimens need to be separated and frozen after 5 days. Unseparated specimens are unsuitable for analysis after this time.

4 mL EDTA Whole Blood
Require dedicated EDTA specimens (no other tests requested).

Centrifuge and separate EDTA plasma samples within 24 hours of collection into a sterile tube.
Transport at 2 - 8 degrees C if transport time from collection is less than 24 hours. Transport frozen if more than 24 hours.
Whole blood, the absolute minimum volume required is 2.5 mL

Paediatric Micro-EDTA Whole Blood
5 full microcollect EDTA tubes required.
Must be full containers or there will be insufficient sample to assay

Reference Intervals
Limit of detection for 650 ul sample volume: 20 - 1.0 E+07 (log 1.3 - 7.0) HIV DNA copies/mL (3 3 - 1.67E+07 IU/mL
Limit of detection for 350 ul sample volume: 50 - 1.0+E07 (log 1.7 - 7.0) HIV RNA IU/mL (8 3 to 1.67E+07 IU/mL

The conversion factor for COBAS HIV-1 is 0.6 copies/IU as defined by the kit.

Uncertainty of Measurement:

+/- 0.2 log copies/ml

Turnaround Time: Within 4 days
.

Assay Method

Testing is performed using the Roche COBAS 6800 HIV test.

Diagnostic Use and Interpretation

HIV Drug Resistance Genotyping
HIV Proviral DNA

Contact Information
Urgent enquiries

In normal working hours (0800-1600 Mon-Fri) contact Clinical Virology via LabLINK (internal extension 22000, external number 09 307 8995).
Outside of normal working hours (evenings and weekends) contact the On Call Clinical Microbiologist via Te Whatu Ora Te Toka Tumai Auckland main switchboard (09 367 0000).

Non-urgent enquiries

Email virology@adhb.govt.nz .

Specimen Transport Instructions for Referring Laboratories

Whole blood in PPT can remain unspun in PPT tubes for no longer than 6hrs at ambient temperature
Within 6 hrs of collection, the tube must be spun at 1100 x g for 20min
On the arrival of PPT tube in virus laboratory, re-centrifuge the PPT tube at 600 x g for 5 minutes prior to aliquoting plasma to the storage tube for further storage in -70 ^o C.
If testing is performed within 5 days, the sample should be stored at 4 ^o C.
If the volume of plasma is less than required amount, transfer collected plasma to a conical microfuge tube prior to 600 x g centrifugation for 5 minutes. Recover remaining plasma without disturbing the pellet.

Last updated at 22:18:31 12/07/2025