How accurate are STI tests?
Our simple home STI test kits are highly accurate & reliable when you:
- follow the instructions carefully;
- wait for the recommended window period before you test;
- complete additional tests in a clinic setting after a ‘reactive’ result.
A ‘window period’ means the time it takes for an infection to show up in tests. This period starts from the time of your sexual health risk - when you think you may have been exposed to infection.
Your samples are sent to our partner laboratory to be processed by specialist technicians. We use the same tests that are used by many NHS clinics.
If you are experiencing any STI symptoms, you should visit your local sexual health clinic.
How accurate are chlamydia and gonorrhoea tests?
Chlamydia and gonorrhoea tests are 99.9% accurate. But it is also important to remember that no test is 100% accurate. If you have any questions about your test results or your risk of infection, contact us
Your test kit could include:
- a vaginal, rectal or throat swab
- a urine sample pot.
How accurate is the syphilis test?
Our blood sample kit gives a very reliable result when done correctly and at the right time.
Blood tests for syphilis are most accurate 12 weeks (3 months) after infection but may show a positive result sooner. If you think you might have been exposed to syphilis, you should test now and do another test after 12 weeks.
Our lab needs 16 drops of blood to run an accurate test. You will need to fill the blood sample tube up to the ‘600’ line. Most people find it easier to get enough blood after:
If you have tested positive for syphilis in the past, it’s likely that you will always receive a positive result from a blood test, even if you’ve had treatment. We recommend that you visit a clinic for an RPR test, which will tell you if you have a new syphilis infection.
How accurate is the HIV test?
Blood tests for HIV are reliable when done at the right time. We offer two types of HIV test which have different ‘window periods’. The window period is the time it takes for an infection to show up in tests.
Blood sample test (results by text) Results are most accurate at least 4 weeks after potential exposure to the infection.
INSTI test (instant results) Results as most accurate 12 weeks after exposure.
If you’re not sure when you might have been exposed, test now and then take another test after 4 or 12 weeks depending on the type of test.
How accurate is a negative result for the HIV test?
The blood sample kit and the INSTI test will give you either: a negative result, or a ‘reactive’ result.
Our HIV tests are very sensitive and a negative result is highly accurate as long as you waited for the correct window period after potential exposure to the infection. So if you have a negative result after the window period then you can be confident that you don’t have HIV.
How accurate is a ‘reactive’ result for the HIV test?
A ‘reactive’ result means that the test has reacted with something in your blood that could be (but is not necessarily) the HIV virus or antibodies to the HIV virus.
We follow the World Health Organisation guidance on HIV testing. This means that we only diagnose HIV after completing three separate tests. These tests look for three different parts of the HIV virus or its antibodies.
If your blood is taken in a clinic, there will be enough blood to do all three tests on one sample. With a home sample kit and the INSTI test, you will only collect a very small sample of blood. This means that the laboratory only has enough blood to do the first of the three tests.
The test that we use is very sensitive, to ensure there are ne false negative results. It is so sensitive that there are some things (for example other infections) that are not HIV infection that may cause a reactive result.
If you have a reactive result, we will ask you to go to a sexual health service where they can collect a larger sample to complete the second and third tests. Between 6% and 35% of reactives will be confirmed as positive in a clinic.
If you are worried about a reactive result, or are anxious about waiting for another test, contact our clinicians. We can talk you through the process and answer your questions.
How accurate are the tests for Hepatitis B and Hepatitis C?
If you think you have been at risk of hepatitis B or C infection during sex, you will need to wait 4 weeks before testing for the most accurate result.
The test we use is about 98% accurate in detecting antibodies for hepatitis B or C. If your test is positive, we will refer you to a liver specialist. They will find out whether you have an active infection or not and organise treatment if required.
If you know that you have been infected with Hepatitis B or C in the past, we’d recommend that you visit a sexual health service to take your test.
If you are a man who has sex with men then we recommend the hepatitis B vaccine. You can arrange this at your local sexual health clinic.
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