HIV antibody and HIV antigen (p24) testing is used to screen for and diagnose HIV infections. Early detection and treatment of HIV infection and immune system monitoring can greatly improve long-term health and survival
A negative test for HIV antigen and/or HIV antibody usually indicates that a person does not have an HIV infection. A negative screening test means only that there is no evidence of disease at the time of the test, however. It is important for those who are at increased risk of HIV infection to have screening tests performed on a yearly basis to check for possible exposure to the virus.
HIV tests that detect only HIV antibody will not detect an HIV infection soon after exposure, during the window period before the development of antibodies. Most people produce detectable levels of antibody 3 to 12 weeks after exposure. If someone is screened with an HIV antibody test too soon, the result may be negative despite the fact that the person is infected (false negative). If an HIV antibody test is negative but suspicion of exposure remains high, then repeat testing using the HIV antigen/antibody blood test may be required.
If someone tests positive on both the initial screen and supplemental testing, then that person is considered to be infected with HIV.
The CDC recommends use of a new testing protocol to screen for and diagnose HIV infection. The following lists the steps and meaning of test results:
Screen for HIV infection using a combination HIV antigen/antibody test, then
Verify a positive with a second HIV antibody test that differentiates between HIV-1 and HIV-2.
If results of the first and second test do not agree, then the next test to perform is an HIV-1 RNA test (nucleic acid amplification test, NAAT). If the HIV-1 RNA is positive, then the test is considered positive.
Get tested and know your partner's HIV status. . . . Have less risky sex. . . . Use condoms. . . . Limit your number of sexual partners. . . . Get tested and treated for STDs. . . . Talk to your health care provider about pre-exposure prophylaxis
People with HIV who know they are infected can get HIV treatment (antiretroviral therapy, or ART) that can keep them healthy for many years. Studies indicate that all people living with HIV, including those with early infection, benefit from ART. Treatment with antiretroviral medications lowers the level of HIV in the blood (viral load), reduces HIV-related illness, and reduces the spread of HIV to others. Taking ART the right way every day can reduce an HIV-positive person's chance of transmitting HIV by as much as 96%.
People living with HIV who know they are infected can also make other decisions that lower their risk of transmitting HIV to a partner. Studies have shown that many people with HIV who know they are infected avoid behaviors that might spread the infection to others with whom they have sex or share needles.
Test Method 1 : Virus isolation and HSV-antibody testingSpecimens removed from virus-transport medium (veal infusion broth with antibiotics) were inoculated onto microtiter plates containing human diploid fibroblasts, and all isolates were typed by monoclonal antibodies, as described elsewhere . The same virus-isolation method was used throughout the study period. The HSV type_specific serological tests were done by Western blot
PCR assayThe PCR assay was a modification of the real-time quantitative fluorescent_probe assay described elsewhere . The swab samples in PCR buffer were thawed and opened, the swab was discarded, and 200 _L of the swab sample was extracted by use of Qiagen columns, as described elsewhere. Ten microliters of the extracted DNA was used in each assay. The primers and probes were directed to the HSV glycoprotein B gene