When are children given an HIV test?
- If your mother and/or father have HIV
- If you come from a country where HIV infections are common
- If something has happened that puts you at increased risk (you have pricked yourself on a syringe or you have had unprotected sexual contact).
- If you have symptoms associated with an HIV infection.
HIV positive or HIV negative?
An HIV test can be positive, negative or sometimes indeterminate. We say the test is
positive if there is HIV present in your blood. This can be confusing because it is, of course, not positive news. If HIV is not present, the test result is
negative.
Sometimes a test is inconclusive. For example, if the result of the first HIV test was positive but that of the second HIV test was not. This can occur in the case of infection with HIV-2 or if the antibodies against HIV are not yet detectable in your blood.
Diagnostic tests
There are two different HIV tests. Blood must be taken for both tests (vene puncture).
1.
HIV particle test. This test (also called the HIV RNA test) shows how many virus particles you have in your blood (viral load). The test also allows you to see whether the treatment is successful. The fewer virus particles there are, the better the medication is working.
2.
HIV antibody test. Your blood can be screened for antibodies against HIV. These antibodies are produced by your own immune cells and are specifically directed against HIV.
Children under the age of eighteen months are only given an HIV particle test. Newborn babies have antibodies against HIV in their blood from their mother, therefore an
HIV antibody test would not tell us anything. From the age of eighteen months, an HIV antibody test is reliable.
Important tests after diagnosis
1.
HIV- RNA VL. This blood test enables you to determine the number of virus particles in your blood (viral load). It allows you to see which phase of the HIV infection you are in. This is necessary in order to know whether it is time to start taking medication. The test also shows whether the medication is successful.
2.
Number of CD4 cells. The fewer CD4 cells in your blood, the worse shape your immune system is in. This also allows you to see which phase of the HIV infection you are in.
When is a child tested for HIV? For example, if HIV occurs in your immediate circle (in one of your parents or in an epidemic area), if something has happened that could cause you to become infected (you have pricked yourself on a syringe or you have had unprotected sexual contact), or in the event of symptoms associated with an HIV infection. Before a blood test is performed, you are given an in-depth consultation and a physical examination.
HIV positive or HIV negative, what does that mean exactly?
An HIV test can be positive, negative or 'indeterminate' (inconclusive). A test is positive if what you are testing for can be detected. Therefore if HIV is present in your blood, the test result is positive. This can be confusing because it is, of course, not positive news. If HIV is not present, the test result is negative.
A test is indeterminate if the result of a HIV test is not clearly positive or negative. This can occur in the case of infection with HIV-2 or if the antibodies against HIV are not yet detectable in your blood (for example with partial seroconversion in the case of an acute HIV infection). The transition of non-detectable to detectable antibodies against HIV in your blood is called seroconversion. It is also possible that the result of a first HIV test was indeterminate or positive but that of the confirmatory second HIV test was not. If you do not have an HIV infection, you can get such a result because the test has reacted to antibodies of an auto-immune disorder, a flu vaccination or an HIV-1-vaccine from the past.
Available diagnostic tests:
1. HIV RNA test. Blood must be taken for this test (also known as an HIV particle test). Umbilical cord blood cannot be used. The screening must be performed several times in order to detect newly acquired infections (for example around birth). This test detects HIV RNA in your blood and shows how many virus particles you have in your blood (viral load, the number of virus copies per milliliter of blood). The viral load also shows whether the treatment is successful; a decrease in viral load means that the medication is working well.
2. Serological screening, or HIV antibody test.Your blood can be screened for antibodies against HIV. These antibodies are produced by your own immune cells and are specifically directed against HIV. Seroconversion is the transition of non-detectable antibodies to detectable antibodies. The 'window phase' is the phase from the moment of infection until seroconversion, the moment when antibodies against HIV are detectable in the blood. With the tests that are currently available, the 'window phase' is four to six weeks.
Children under the age of eighteen months are given an HIV RNA test. Newborn babies have antibodies against HIV in their blood from their mother, therefore an HIV antibody test would not tell us anything. From the age of 18 months, HIV antibody test is reliable.
Important tests post diagnosis:
1. Viral load test, or HIV RNA VL. This blood test enables you to determine the number of virus particles in your blood (viral load). The test can be used to see which phase of the HIV infection you are in and to monitor the progression of the illness. This is necessary in order to know whether it is time to start taking medication. The test also shows whether the medication is successful.
2. Number of CD4 cells.The number of CD4 cells per mm3 of blood provides an indication of the deterioration of your immune system. The fewer CD4 cells in your blood, the less effective your immune system. You can also see which phase the HIV infection is in and how the infection is progressing.
