Key points at a glance
🧪 Laboratory test
After six weeks, an HIV infection can be ruled out with certainty.
⏱️ Rapid and self-tests
The result is available after a few minutes. HIV can be ruled out with certainty after twelve weeks.
📦 Test submission
You take the samples at home and send them to the laboratory for analysis.
🧬 PCR test
PCR detects HIV directly and is primarily used to monitor HIV treatment.
There are various ways to get tested for HIV. These include laboratory tests, rapid tests, self-tests, post-by-post tests and PCR tests. The methods differ in terms of what exactly they detect, how quickly a result is available, and when an HIV infection can be reliably ruled out.
Most HIV tests are antibody tests. These test the blood for antibodies against HIV. A laboratory test can reliably rule out an HIV infection six weeks after the last instance of risky behaviour. Rapid tests and self-tests require twelve weeks to do the same.
If a recent HIV infection is suspected, tests that directly detect HIV or components of the virus can also be used. These include, for example, the PCR test.
Which HIV test is right for you depends on your situation. When choosing a test, you can seek advice from organisations such as AIDS support groups, Checkpoints, public health authorities, doctors’ surgeries or clinics specialising in HIV, for example.
HIV laboratory test (detection of HIV antibodies)
For an HIV laboratory test, blood is taken from the crook of the arm and then analysed in the laboratory. Modern laboratory tests look for antibodies against HIV and also for a specific component of the virus.
A so-called antigen-antibody test can be carried out around two weeks after a possible exposure to HIV. However, at this early stage, it is not yet possible to rule out an infection with certainty.
That is why the ‘window period’ is important:
- After 6 weeks: An HIV infection can be ruled out with certainty.
If the laboratory test is positive, a confirmatory test is carried out straight away in the laboratory. You will usually have to wait a few days for the final result.
HIV rapid test (detection of HIV antibodies)
A small amount of blood from the fingertip is sufficient for a rapid HIV test. The result is usually available within a few minutes. An HIV infection can be detected by a rapid test as early as around three weeks after the last high-risk exposure.
The window period is important:
- After 12 weeks: An HIV infection can be ruled out with certainty.
If the rapid test is positive, the result must be confirmed by a laboratory test. This involves taking a blood sample from the crook of the arm. The result of the confirmatory test is usually available after one to two days.
HIV self-test (detection of HIV antibodies)
An HIV self-test is a rapid test that you can carry out yourself at home. To do this, you take a small blood sample from your fingertip and place it in the test kit. You can read the result after a few minutes.
The window period is important:
- After 12 weeks: An HIV infection can be reliably ruled out following the last high-risk exposure.
If the self-test is positive, the result must be confirmed by a further test.
HIV postal test (detection of HIV antibodies)
With a home HIV test, you take the samples yourself at home. You then send them to a laboratory for analysis. HIV tests are often combined with tests for other sexually transmitted infections.
In the offer s.a.m. health At Deutsche Aidshilfe, for example, this is how it works:
- Register online: You register and select a participating checkpoint.
- Get advice: A brief telephone consultation takes place before the first test.
- Taking samples at home: A small blood sample from the fingertip is required for HIV and syphilis. In addition, urine samples and swabs from the throat, anus or vagina can be tested for gonorrhoea and chlamydia.
- Sending in samples: The test sample is sent to a laboratory in a pre-paid envelope.
- Get the result: A few days later, you’ll receive the results via your s.a.m health Checkpoint. If all the results are negative, you’ll receive a text message. If a result is positive, you’ll be asked to call back.
s.a.m health is particularly suitable for people who wish to get tested regularly for HIV and other STIs. If you wish, you can receive a reminder to order a new test kit every three, six or twelve months. You can stop using the service at any time.
The first test kit currently costs 75 euros. Each additional test kit costs 59 euros. This price includes advice, test materials, postage, delivery and laboratory analysis.
HIV PCR (direct HIV detection)
The PCR test does not detect antibodies, but looks directly for HIV. It is mainly used to monitor whether HIV treatment is effective. Highly sensitive PCR tests can detect as few as 20 copies of HIV per millilitre of blood serum.
A PCR test can also be used as a confirmatory test following a positive antibody screening test. If more than 1,000 copies of HIV per millilitre of blood serum are detected, the result is considered confirmed.
PCR testing may also be important for newborns of mothers with HIV. During the first 18 months, antibody screening tests always yield a positive result for these babies because they still have their mother’s antibodies in their blood.
PCR is generally not suitable for definitively ruling out an HIV infection. Antibody tests, such as laboratory tests, rapid tests or self-tests, are used for this purpose.
Frequently asked questions
What types of HIV tests are available?
There are HIV laboratory tests, rapid tests, self-tests, post-by-post tests and PCR tests. The methods differ in terms of how they are carried out, how results are interpreted and the window period.
When can a laboratory test reliably rule out HIV?
An HIV laboratory test can reliably rule out infection six weeks after the last high-risk exposure. An HIV infection may be detectable as early as around two weeks after a possible exposure.
When are rapid tests and self-tests reliable?
An HIV rapid test or HIV self-test can reliably rule out infection twelve weeks after the last high-risk exposure.
How does a post-by-post HIV test work?
The samples are taken at home and then sent to a laboratory. Depending on the service offered, tests may be carried out for other sexually transmitted infections as well as HIV. The window period depends on the testing method used.
What is an HIV PCR test used for?
A PCR test directly detects HIV. PCR is primarily used to monitor HIV treatment and as a confirmatory test. Laboratory tests, rapid tests or self-tests are generally used to rule out HIV infection with certainty.
