Positive or negative? A new HIV test should provide more certainty. Patients now only have to wait six weeks instead of the previous three months before they can be tested. However, not everyone can take the test.
- HIV positive or negative is a scary question.
- Previously, you had to wait three months to be tested.
- Now it’s much faster.
Unprotected sex , a prick with a needle – and the fear of the AIDS pathogen is there. Now there should be certainty faster. Six weeks of fear instead of three months: An HIV test can now provide security much earlier in Germany. Corresponding guidelines now apply, as the Deutsche Aids-Hilfe announced on Friday.
“So far, people have been told: you have to wait three months, otherwise it is not safe,” said Holger Wicht, spokesman for the German Aids Aid. The number of viruses and antibodies is only increasing gradually. But now the responsible medical societies have shortened the required deadline.
More sensitive process
“This is a relief for many people and can motivate them to take the test,” says Armin Schafberger, medical expert at Deutsche Aids-Hilfe. The reason for the shorter time window between a risk situation and a diagnosis is a more sensitive and combined procedure and multiple reviews of this test.
This Ag-Ab combination test checks for antigens (Ag) and antibodies (Ab). It detects antibodies in the blood earlier and more reliably than older versions. It can also display an antigen: the p24 protein of the AIDS pathogen. It can only be found temporarily – but after about two to three weeks after infection.
People can get tested earlier
These tests are not new, however. According to German Aids Aid, they have been on the market since 1997 and almost all laboratories are now using them. What is new, however, is that people who want to be tested for the HI virus can now do so earlier.
“The three-month deadline that used to apply was simply a safety factor,” says virologist Jörg Hofmann from the Charité University Hospital in Berlin. “Of course you want to be sure that the test does not reveal anyone who was infected as HIV-negative – just because you tested too early.” Enough research should have shown that the test works for the majority of people after just six weeks.
In England you have to wait four weeks
With their statement, the German Association for Combating Viral Diseases (DVV) and the Society for Virology (GfV) are following the European guidelines that were changed a year ago. In Great Britain, the diagnosis period for the combined test has even been reduced to four weeks.
In Germany, however, something has changed after the DVV and GfV statements. If the combined test works, those affected can get confirmation faster than before.
If the first test reveals an infection, it cannot be determined whether it reacted to antibodies or to the antigen that was present before the antibodies were formed. If it is the antigen, the previously specified confirmation procedure – the Western blot test – cannot recognize it. So people had to wait in uncertainty until antibodies could also be detected.
Additional genetic evidence should bring certainty
However, there is a method that can confirm a result even without antibodies: genetic evidence (via PCR). If the Western blot test remains negative, genetic evidence should now be made according to the new guidelines. This is already common practice: after a reactive addiction test, many doctors have initiated such a test immediately, according to the current AIDS report of the German AIDS Association.
“But that has not yet applied to the registration form,” says Schafberger. “But you want to report the infection to the Robert Koch Institute straight away and give the patient a clean result right away.”
Just a blood draw
Uncertainty is a burden. “That is why it is psychologically good if you know earlier,” says Klaus Überla, head of the Virological Institute at the University Hospital Erlangen.
He also points out another relief for patients: a sample should now be taken for both tests, the search test and the confirmation. “Then the person concerned does not have to be written to again, to give blood again.”
Exceptions to the test
For HIV rapid tests and older test versions, however, there remains a diagnostic window of twelve weeks. The DVV and the GfV also make two exceptions to the shorter period: It does not apply to people who are infected with a rare HIV variant, namely HIV-1 group 0 or HIV-2. And even those who already have immunosuppression or an immunodeficiency with antibody formation disorders cannot rely on the test after six weeks.
According to an estimate by the Robert Koch Institute, around 80,000 people in Germany were living with HIV or AIDS in 2013 and around 14,000 had the virus without knowing about it. The first HIV test was patented in the USA in January 1985 and approved in Germany a few months later.