The HIV Characterisation Laboratory has both diagnostic and research and development roles.
In the diagnostic laboratory, quantitative HIV-1 RNA testing is used to monitor disease progression, to help determine when to initiate treatment with antiretroviral drugs and to monitor the virological response to these drugs. Qualitative HIV DNA detection is also available and may be used as an adjunct to serological testing when recent HIV infection, including neonatal infection, is suspected.
Sequencing (genotyping) of regions of the genome can also be performed when failure of therapy is thought to be associated with the development of drug resistance. Currently the sequences amplified for this purpose are the protease, reverse transcriptase and transmembrane protein coding regions.
Australian HIV testing laboratories assesses the impact of sequence changes on susceptibility to the current drugs using a rules based algorithm (the CREST algorithm). The laboratory supplies the HIV subtype on each sequence amplified.
The HIV Characterisation Laboratory also has an active research and development program. A quantitative HIV-2 RNA assay has been recently developed to help follow disease progression in the small number of Australian residents currently infected with this virus.
A major area of interest is the transmission of drug resistant virus and the subsequent response to antiretroviral therapy of individuals infected with these viruses. The laboratory also has a significant collaboration with the National Centre for HIV Epidemiology and Clinical Research, acting as a testing site for this organisation and performing studies on cohorts of patients involved in its clinical trials (Middleton, 2001 ; Birch, 2003).