Types of hiv tests
There are 4 types of hiv tests.
- A test for proteins on the surface of the virus (antigens) for example protein 24 antigen (p24), this test is rarely used.
- A test for an immune response of the body to the virus (antibodies), this test is also rarely used.
- A combined antibody-antigen test, this test is most used.
- A test for genetic material of the virus (HIV-RNA), this test is more expensive, but can earlier detect an infection.
The hiv-RNA test
The HIV-RNA test is done by PCR. PCR means Polymerase Chain Reaction, this test detects directly the genetic material of the virus (HIV) in the bloed, called RNA. Also the viral load can be determined with this test. The viral load is the amount of virus-particles in the blood.
When someone has symptoms related to HIV, the HIV-RNA test will be positive. This is because HIV symptoms are related to the amount of virus-particles in the blood (the viral load).
Als when someone doesn’t experience symptoms the HIV-RNA test can detect the virus, even before the body made antibodies against HIV. Thats why this test had the shortest window period of all HIV tests. The window period tis the time between infection and the moment the test can reliable detect the infection.
Window period hiv-RNA test
The RIVM (rijksinstituut voor Volksgezondheid en Milieu) says that an HIV infection can be detected 9 till 11 days after the infection with an HIV-RNA test.
Dutch general practicers (NHG) do not have a specific window period for the HIV-RNA test in their protocol. The say the window period for a combined antibody-antigen test is maximum 3 months. Most of the time the period is a lot shorter but it depends per person. About the HIV-RNA test (viral load) the NHG says that it has a shorter window period than the combined test.
Besides that, studies about the window period of the HIV-RNA test is in most cases 7-14 days.
When combining all these results we say, 14 days after the potential infection you can test reliable for HIV with the HIV-RNA test.
Do you want to test for HIV with the HIV-RNA test? That is possible at the OneDayClinic with the HIV-RNA rapid test. You receive the results in 2 hours.
Source: (1) Delaney, K., Hanson, D., et al. ( 2017) Time Until Emergence of HIV Test Reactivity Following Infection With HIV-1: Implications for Interpreting Test Results and Retesting After Exposure. Clin Infect Dis. 2017 Jan 1;64(1):53-59