If you’ve had unsafe sex, you’re probably feeling anxious and uncertain about the best course of action. You're also probably unsure about your risk of having contracted HIV.
Here’s what to do:
When to have an Aids test
If you’ve had unprotected sex, it’s very important that you get tested to find out if you’ve been infected.
If you have been infected with HIV, it takes a while after you had unprotected sex before signs of it show up in your blood, and before these signs can be detected by a test. The period between infection and when it can be detected in the blood is called the ‘window period’.
In most cases of HIV infection, the window period is about four to six weeks. However, in some individuals this period is longer: several months. For this reason, even if you test negative for HIV at your first test, you should be tested again at three months to make sure you are not infected. It may even be recommended in some cases that you go for a third test at six months.
There are basically three types of HIV tests available.
The antibody test
The antibody test is the one that is most widely available in South Africa, and is what will be used at most government clinics.
For this test to work, you need to wait about six weeks after you had unprotected sex. Even if you test negative for HIV infection, to make quite sure you will need to have a second follow-up test.
The combination test
The combination test (also known as the combination antibody-p24 test) is only available through private doctors and laboratories.
This test is sensitive enough to test for HIV infection at three weeks after you had unprotected sex. Even if you test negative for HIV, you still need to have a second follow-up test to be sure of your HIV status.
The PCR test
There is an HIV test, called the PCR test, that is sensitive enough to pick up whether you are positive for infection ten days to two weeks after having unprotected sex. However, this test is expensive and not widely available; you would need to find a private doctor who performs it.
Even if you get a negative test result with the PCR test, you still need to have a second follow-up test to be sure of your HIV status.
When can I have sex again?
You can have sex while waiting for the window period to pass, and while waiting for the results of your test. However, at this time you should take particular care to practice safe sex; you should also discuss the fact that your HIV status is uncertain with any sexual partners.
Remember: you will only know your HIV status for sure after your second follow-up test at three months.
What about taking drugs if I’ve had unprotected sex?
In cases of very high risk, for example if you’ve had unprotected sex with someone you know (or have good reason to suspect) is HIV-positive, you should consult a doctor as soon as possible about taking drugs to help reduce the risk of HIV infection from setting in. This is known as post-exposure prophylaxis.
In such cases, for example when a person has been raped, a baseline HIV test is done. If this test shows the person is HIV-positive, it means they were already infected prior to being raped. This is important for the doctor to know because the treatment is different for someone who is already known to be infected.
(Olivia Rose-Innes, Health24, October 2005)
Reviewed by Dr Jane Yeats, Department of Virology, University of Cape Town
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