Instant HIV Test
An Instant HIV Test can offer accurate results within 20 minutes.
We utilise fourth-generation HIV test which can detect both HIV 1/2 antibody and HIV-1 p24 antigen.
All results are highly confidential and will not be shared with anyone unless you ask us to.
It is also called the HIV DUO or HIV COMBO test.
Same day appointments
In London & Birmingham Clinic
Highly confidential service
And discreetly located clinics
Specialists in sexual health
From busy NHS clinics
When can I have an Instant HIV test?
We recommend waiting 45 days before opting for a 4th generation instant HIV test as having this test earlier may result in a false negative result.
As you can see from the graph below, the HIV p24 antigen appears earlier than the antibody. As a result, it is possible to accurately test someone earlier than before.
However, it is important to note that the p24 antigen is transitory and after a certain time period, it has no additional advantage over a 3rd generation HIV test.
How accurate is the Instant HIV test?
There are two types of 4th Generation HIV tests that we offer:
Lateral Flow (Point of care – routine)
This test is used in our routine packages for quick and accurate results.
- Turn around time: 20 minutes
- Specificity (% of true negatives): 100%
- Sensitivity (% of true positives): 95%*
ELISA (Lab based)
We also have access to a lab based HIV test should you need it (at the same cost as the instant test).
- Turn around time: 4 working days
- Specificity (% of true negatives): Approx. 99.5%
- Sensitivity (% of true positives): Approx. 99.7%
*Although the manufacturers’ information leaflet states a sensitivity of 99%, our own experience and independent research is consistent with a sensitivity of 95%.
What if my test is reactive?
In the event that your Instant 4th generation HIV test is reactive (whether this is the instant or lab based test), we will run a HIV-1 RNA PCR test for you to confirm the diagnosis and send a sample to our partner lab for a HIV LIA test to elicit further information.
Our consultants are specialists in HIV Medicine and have decades of experience in treating patients with HIV in all its stages. Therefore, in the event your test result is positive, you are in the best hands to be looked after.
Can this test distinguish between HIV-1 and HIV-2?
No. This test looks for the evidence of both HIV-1 and HIV-2 antibodies together. This means if your test is reactive, we will carry out a further test to determine which type of HIV you have.
How is it different from the 10 Day HIV test?
The 10 day HIV test (i.e. HIV-1 RNA PCR test) looks for the HIV virus itself (i.e. HIV RNA & Pro-Viral DNA) and it is accurate from 10 days post-exposure.
The 10 day HIV test also does not produce any false-positive test results. And is more suited for those who want the most accurate HIV test result in the shortest amount of time possible (3 hours in our Birmingham clinic).
The Instant HIV test (4th Generation) looks for the HIV antibodies as well as the p24 antigen – this is accurate from 45 days post-exposure.
Is this a legitimate test?
Yes. Our 4th generation HIV tests are CE marked, FDA approved and WHO approved.
If you’re at high risk of acquiring HIV, we can look for HIV after 10 days of possible exposure.
The HIV-1 Viral Load measures the amount of the HIV virus in your blood – only for HIV positive patients.
Page reviewed by Dr. Manoj Malu (Clinical Director)
Last reviewed date: 18 March 2021
Next review due: 18 March 2024
Whilst this content is written and reviewed by sexual health specialists, it is for general guidance only. It is not intended to replace the advice of your clinician.
Reference & Further Reading
- PLoS One: Evaluation of two 4th generation point-of-care assays for the detection of Human Immunodeficiency Virus infection
- AIDSmap: How accurate are rapid, point-of-care tests for HIV?
- I-Base: Appendix 1: Different types of HIV test | Guides
- Journal of Virological Methods: Evaluation of a 4th generation rapid HIV test for earlier and reliable detection of HIV infection in pregnancy
- Journal of Clinical Virology: The risk of a second diagnostic window with 4th generation HIV assays: Two cases
- Clinical Laboratory: Multicenter evaluation of a new 4th generation HIV screening assay Elecsys HIV combi. – Abstract
- Journal of Clinical Virology: Pooled nucleic acid testing increases the diagnostic yield of acute HIV infections in a high-risk population compared to 3rd and 4th generation HIV enzyme immunoassays
- Journal of Virological Methods: Improved performance of seroconversion with a 4th generation HIV Antigen/Antibody assay