Private HIV Tests
In 2019, it was estimated that there are 105 200 people living with HIV in the UK.
94% of these individual have been diagnosed, and so know that they have HIV. This means that around 1 in 16 people living with HIV in the UK do not know that they have the virus. We encourage all people who have had an unprotected sexual encounter to have an HIV test.
Early diagnosis and treatment of HIV is important. Modern antiretroviral therapy means that those living with HIV if managed well, have the same life expectancy as those without HIV.
98% of people diagnosed with HIV in the UK are on treatment, and 97% of those on treatment have undetectable levels of the HIV virus. This means they can’t pass the virus on. Of all the people living with HIV in the UK, 89% are virally suppressed.
We field many questions about the accuracy of these tests. When we talk about the accuracy of a test, we take into account the published Sensitivity - how many people who actually have HIV, test positive, and Accuracy- how many people who actually don’t have HIV, test negative.
HIV INSTI test
A very rapid reliable test with results in 1 minute
This CE-marked test has a sensitivity of 99.8% and an accuracy of 99.5% at 3 months.
It can take from 3 to 12 weeks for an individual to develop enough HIV IgM antibodies to HIV after having contracted it to be detectable by the HIV INSTI. 97% of people will develop enough antibodies during this 3 month period.
You can test before this 3 month period is over but we advise you to test again at 3 months or after.
HIV Duo Test – HIV 6 week Test
The HIV antibody/p24 antigen Duo Test is an excellent, accurate and inexpensive HIV test that reliably detects HIV infection that occurred just 28 days prior to the test.
This HIV test is known as the ‘Duo’ because it tests for both HIV antibodies as well as the ‘HIV P24 antigen’. The HIV p24 antigen is a core HIV viral protein that becomes detectable at approximately 10 days post-exposure, peaks at 16 days or so, and then remains at high level for 8 to 10 weeks post-exposure. It will then fluctuate over the rest of the course of the illness.
The HIV p24 antigen is extremely useful in combination with an HIV antibody test in determining early on whether an individual has been infected with HIV. The HIV DUO test is extremely accurate at 28 days and is now the test recommended by the UK Guidelines on HIV testing.
We send a small blood sample to our laboratory and the results are usually available in a few hours.
The HIV DUO test including p24 antigen is rated as 99.89% accurate at 28
HIV 1 & 2 RNA PCR Test – Results from 10 Days
This multiplex or PCR (polymerase chain reaction) test works by detecting minuscule amounts of DNA of the HIV virus and multiplying it to enable it to be analysed. This is highly accurate and the gold standard of early HIV 1 & 2 testing.
This takes 3-5 working days to come back.
Rapid Xpert HIV-1 RNA qualitative early detection HIV testing from 7 days with same-day results
For most patients rapid answers for their worries of HIV infection is important.
Xpert HIV–1 Qual is a qualitative test that provides on-demand molecular testing for early HIV 1 diagnosis. Based on the GeneXpert technology, Xpert HIV–1 Qual provides a total nucleic acid-based test for RNA and proviral DNA.
This differs from the other early detection by PCR/NAAT HIV test we offer in a number of ways:
Positive: Rapid processing – same-day results
Negative: Tests for HIV 1 only. The HIV 2 virus is much less common but still important to be aware of. Please read more about this below.
It has similar accuracy for HIV 1 diagnosis at 10 days as the PCR/NAAT test.
Please see this link for more information: https://www.cepheid.com/uk/cepheid-solutions/clinical-ivd-tests/virology/xpert-hiv-1-qual
When is HIV testing complete?
HIV testing has developed enormously over the last 30 years since the appearance of the HIV/AIDS epidemic.
There are many HIV tests in use. We try to concentrate on using the most modern tests, with the most supporting evidence regarding their use, our own collective personal experience of using them and also the varying Guidelines and advice from the UK Advisory Groups. Advice and statements from the CDC in the US is considered as valuable but is commonly incomplete and out of date. Consequently, we rely heavily on modern advice obtained from within the UK and also published in world-class medical journals.
Some of the advice published may appear to be contradictory, so again we have tried to develop a consensus view, using our combined huge experience of the tests available.
The UK Guidelines on HIV Testing published in September 2008 have emphatically recommended the use of 4th generation combined HIV p24 antigen and HIV antibody tests (HIV DUO tests) as the test of first choice, citing the very distinct benefit of the earlier diagnosis of HIV using these tests as opposed to the older 3rd generation HIV antibody tests. The 4th generation combined tests will shorten the time from infection to diagnosis by 1-2 weeks over the older 3rd generation HIV tests. The older 3rd generation tests are excellent and will still identify the majority of new HIV infections by 6 weeks.
The UK HIV Post Exposure Prophylaxis Guidelines published in October 2008 are in agreement with the above HIV testing Guidelines with respect to the use of the 4th generation combined HIV p24 antigen and HIV antibody tests except they set the interval for definitive testing at 12 weeks post exposure.
Both lots of Guidelines have been written by different groups but with a crossover of experts. So as with many other issues in life, complete agreement is sometimes not possible.
From Dr Dan’s point of view, using as described above the combined knowledge and experience of the team we regard the HIV DUO test as a conclusive HIV test at 6 weeks or beyond in almost all circumstances. In situations where a patient has had an exceptionally high level of HIV exposure and has symptoms which we regard as suggestive of an acute HIV infection, we will encourage the patient to re-test at an appropriate interval which we will decide with the patient. However, it is almost always the case that a negative HIV DUO test at 6 weeks or more will be conclusive and will not need repeating.
