What is HIV antibody testing?
What is HIV antibody testing? After HIV enters the human body, the human immune system can produce corresponding HIV antibodies. By detecting the HIV antibody in the blood, you can diagnose whether you are infected with HIV. This serological detection method is HIV antibody detection. The test result of HIV antibody is positive, suggesting that HIV is infected.
The purpose of counseling before HIV antibody testing
What is HIV antibody? HIV antibody is an examination item in AIDS screening, which will be tested before operation or during pregnancy test. After people are infected with HIV, they will produce corresponding antibodies-HIV antibodies, which can exist stably for a long time and can be detected except for a short "window period" in the early stage.
HIV in AIDS patients mainly exists in the blood, semen, vaginal secretions, pleural effusion, cerebrospinal fluid and milk of infected people and patients. The human body is infected with HIV mainly through the following three ways: sexual transmission (including homosexual, heterosexual and bisexual transmission), blood and blood products (including intravenous drug use and interventional medical procedures) and mother-to-child transmission.
What are the HIV antibody detection methods?
What are the HIV antibody detection methods? There are five main HIV antibody detection methods:
1, HIV antibody screening test (ELISA): high sensitivity, possible false positive. Patients with positive initial screening should be confirmed by confirmation test.
2.HIV antibody confirmation test (WB): According to WB, WHO can be judged as positive as long as there are two env bands.
3.HIV-RNA: the sensitivity is 100%, but occasionally false positive occurs, but the false positive result is usually lower than 2000cp/ml, and the viral load in acute infection period is usually very high, with an average of 106cp/ml.
4.p24 antigen: It is helpful for early diagnosis and has high sensitivity and specificity.
5. Rapid detection test: whole blood or capillary blood can be collected, and the results can be obtained in 15-30 minutes. But the false positive and false negative rates are high, so it is not used as a routine test.
HIV antibody detection time
When will the HIV antibody test be conducted? It usually takes 2-4 weeks to detect HIV antibody after testing high-risk behaviors. The later the time, the higher the accuracy of HIV antibody detection; Most people infected with HIV can produce enough antibodies after 4 weeks.
Scientific research shows that if the initial examination is done 2-4 weeks after high-risk behavior, if the result is negative, the infection rate of 98% can be ruled out; After 8 weeks, if the result is negative, 99.99% infection rate can be ruled out. Therefore, people who suspect that they have AIDS, it is best to make a final review after 3 months, and negative results can be completely ruled out.
Is HIV antibody testing valuable?
If infected with HIV virus, HIV antibody test results are positive, and healthy people's HIV antibody test results are negative. HIV antibody detection can be combined with other related tests to assist diagnosis. Laboratory examination of AIDS patients: anti-HIV antibody positive, CD4 lymphocyte count.