The nucleic acid test is a very accurate way to test for HIV infection. Once the HIV viral load is detected, the patient is diagnosed with HIV and should be treated with antiviral drugs as soon as possible. However, because nucleic acid testing is expensive, most of the initial screening for HIV in China is done by testing for HIV antibodies. Antibody testing is usually available about 3-4 weeks after infection. Therefore, it is recommended that you go to the hospital for antibody screening about 4 weeks after having high-risk behavior.