Sexual Health Clinic / HIV (AIDS) / Testing

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.