5 mL plain blood. This test is carried out only on screened reactive / equivocal samples. Samples submitted by a referring laboratory must be accompanied by screening results.
Refrigerate samples if delay in transporting to laboratory is anticipated. Do not freeze.
4th generation Ag/Ab assay(s) ± Immunochromatographic Ab differentiation assay
Reported either as:
1) HIV Supplementary test
No serological evidence of HIV infection.
Consider repeat screen as indicated by exposure history & risk factors.
Likely non-specific reactivity in low risk individual. Consider repeating a further sample for HIV screen in 6 weeks (after window period for screening assay) as determined by clinical findings & risk factors.
2) HIV Ab Confirmation
May indicate acute infection if recent high risk exposure. Send a sample for NAAT and repeat HIV screeen in 6 weeks.
For low risk individual, may represent non-specific reactivity. Repeat HIV screen in 8 weeks after window period for the Ab differentiation assay.
b) HIV-1 / HIV-2 Positive
Serological evidence of HIV infection.
1 - 5 days
Monday, Wednesday and Friday