How reliable is the DUO HIV test?
The DUO test is an HIV test that looks for antibodies for HIV-1 and HIV-2 and also looks for evidence of the p24 protein which is on the surface of the HIV particle.
The advantage of testing for p24 is that this indicator of HIV infection can be detected earlier than with tests that only looked for HIV antibodies. Four weeks after exposure, the test is likely to detect 95% of actual infections. The other 5% would show positive within three months of infection.
This study reports that the test was 100% accurate if you get a negative result, and 94% accurate if you get a positive result. As with other types of HIV tests, a positive result need to be confirmed with a different test.
A negative result would only need to be confirmed with a second test if you were exposed less than three months ago. As with all antibody tests, the results relate to your HIV status three months before the test.
A case report of the DUO test taking more than 4 week to generate a positive result, emphasises the importance of confirming a negative result from any test used less than three months after the exposure risk, with a follow up test 3 months later.
The DUO test has no particluar advantages over other routine test when infection is unlikely to have been recent, because p24 is only detected for a short time after infection, and before HIV antibodies can be detected.