I would like to know if Early Screening Ab/Ag ( Microparticle Enzyme Immuno-Assay / Electrochemiluminescence test invariably detect both lgM and lgG antibodies? or just the lgM that dissipate over time?
I understand that igM are the first antibodies to be formed and then they dissipate in a couple of weeks to be replaced by lgG antibodies that stay in system forever detectable.
Also how indicative would such early screening test be ( especially it's antibody part) @ day 50 of exposure? ( though i know it should be followed up by another one @ 3 months) could you put a percentage number to it?
A help in this regard would be highly appreciated.
Hello and thank you for posting your medical question on E health forum.
HIV is diagnosed based on the serological detection in the blood samples. It is not diagnosed on the basis of nonspecific signs and symptoms.
A person after exposure to HIV can get tested as early as 4 weeks to 12 weeks with the ELISA for HIV antibody test. 90% of normal individuals who have HIV exposure, will seroconvert within 4-6 weeks. The sensitivity of the ELISA test is 99.9%.
Testing for HIV testing with HIV ANTIBODY 1/2 and P24 COMBO TEST can be done within 20-28 days of exposure (an average of 5 days before ELISA).
The sensitivity of this test is EXCELLENT (100%). Hence the possibility of false negative or false positives when done after 4 weeks is low.
P24 antigen of HIV : Levels of p24 antigen increase significantly at about one to three weeks after initial infection. HIV antibodies are not seen during this time frame. hence the p24 test is useful to diagnose infection much earlier than the HIV antibody tests alone.
Antibodies for HIV are not present before 4 weeks post exposure
In your case if the ELISA test is done at 50 days (more than 6 weeks post exposure), the ELISA test result would be valid and you will be HIV FREE.
You will not need further testing, anymore. Any repetition of tests will definitely be negative at this point.
If you still have doubts, you might consider to consult with your doctor who can provide reassurance and also can clear all your doubts that you may have.
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