Actual UK Guidelines.
Post-test discussion
The need for a repeat HIV test if still within the window period after a specific exposure should be discussed. Although fourth generation tests shorten the time from exposure to seroconversion a repeat test at three months is still recommended to definitively exclude HIV infection.
http://www.bhiva.org/documents/Guidelines/Testing/GlinesHIVTest08.pdf
I thought I should add the new BASHH guidelines, for the exact wording
As you will see the wording "conslusive" is not mentioned, and its replaced with "definitively exclude".
BASHH Statement on HIV window period
15 March 2010
HIV testing using the latest (4th generation) tests are recommended in the BHIVA / BASHH / BIS UK guidelines for HIV testing (2008). These assays test for HIV antibodies and p24 antigen simultaneously. They will detect the great majority of individuals who have been infected with HIV at one month (4 weeks) after specific exposure.
Patients attending for HIV testing who identify a specific risk occurring more that 4 weeks previously, should not be made to wait 3 months (12 weeks) before HIV testing. They should be offered a 4th generation laboratory HIV test and advised that a negative result at 4 weeks post exposure is very reassuring/highly likely to exclude HIV infection. An additional HIV test should be offered to all persons at 3 months (12 weeks) to definitively exclude HIV infection. Patients at lower risk may opt to wait until 3 months to avoid the need for HIV testing twice.
Dr Keith Radcliffe Dr Simon Edwards
Chair, Clinical Effectiveness Group Chair, BASHH HIV Special Interest Group
Please please we need o update the knowledge in regard to P24 Antigen.
1. It does not disappear just like that. Once antibobies are produced the P24 antigen remain TOGETHER with the antobodies ... for up to 2 months and even longer.
2. DUO/Combi tests are designed to detect both or individual parts of the test.
3. The DUO/Combi test covers ANY lag or cross over period between P24 being present and the creation on Antibodies.
4, In March 2010 The British HIV Association; the British Association for Sexual Health and HIV and the British Infection Society have published new testing guidelines for HIV in the UK. 28 day negative results are conclusive. But if clarification is required by the idividual then a 12 week test should be offered.
The antigen portion of the DUO test is only good up to 3 weeks after infection. When the antibody production begins the antigens are no longer detectable and there may not be enough antibodies produced at that time to be detected by the antibody portion of the test.
Yes. I agree with you. To confirm, a test is at 3 months is good. But a HIV DUO test is better than a HIV Antibody Test at three months. All doctors, medical professenels, HIV Experters are recommending for HIV DUO
If a DUO test does not detect HIV in 28 days it does not rule out that anyone may still be infected. Early detection does not have anything to do with a conclusive negative test. The guidelines to HIV test is still 3 months.
The British HIV Association; the British Association for Sexual Health and HIV and the British Infection Society have published new testing guidelines for HIV in the UK.
The consensus advice recommends the use of an HIV DUO test (4th generation combination antibody and p24 antigen) as a first line test because it has the advantage of reducing the window period to one month (28 days).
visit: http://www.bhiva.org/cms1222621.asp
HIV DUO test is NOT approved in the US.