Is my HIV test after 20 months still accurate?

Question

Hi doctor,

I am a male. I had unprotected vaginal sex single exposure with a girl. Nine months later, I found she is HIV positive. My question: I have read that after a certain window period (three months after getting negative), the result is conclusive, and even after six months, confirmation is definitely negative. But, why are all these other people saying you can go years without showing positive and that is really freaking me out big time. Is it true that it takes years to come up positiv,e or does it only take six months to know it 100 %? What is true? Also, there is a doctor who says no test is 100 % reliable.

I am still 15 months post-exposure. HIV RNA PCR qualitative tests are all negative. Twenty months post-exposure, the HIV-Alere combo test result is negative. Any further test is needed?

I am negative now. Will my result change in the future? What is a 100 % window period? Please clarify my doubts.

Thank you.

Answer 1

Hi,

Welcome to icliniq.com.

The accuracy of your HIV (human immunodeficiency virus) test depends on the type of test used and when it is taken. After HIV enters the body (day 0), it travels to the nearest lymph nodes and begins replicating around day 7. This triggers the release of p24 antigens, core proteins of the virus, which are detectable by certain tests. In response, the body starts producing HIV antibodies, which typically become detectable between 15 and 23 days after exposure. However, there is a brief period, theoretically between 23 and 28 days, when the antibodies begin to neutralize the antigens.

During this time, there is a very small chance of a false negative result, less than 0.001 %. This is why taking a fourth-generation HIV test (which detects both p24 antigens and antibodies) after 28 days is considered highly reliable, with around 99 % accuracy. In any medical field, 100 % certainty is rarely guaranteed. Legally and clinically, no test can promise 100 % assurance. However, with a negative fourth-generation test result after 28 days, no further testing is generally needed. You are considered 99.99 % negative, and a future change in result is highly unlikely. The "window period" refers to the early phase when the virus may not yet be detectable.

I hope this helps.

Kindly revert so I can assist you further.

Thank you.