Wednesday, July 1, 2015
HIV and AIDS
Negative Results After Seroconverting Following Risky Behavior
I had a homossexual encouter 7 weeks ago that involved unprotected anal penetration (I was the active/top) and there was blood although we didn`t quite know whose. I`ve spent the time since then freaking out and knowing all the symptoms of seroconversion, started noticing them in me. 5 weeks ago my armpit glands got very swollen, tender and red, and I`ve had malaise and occassional night sweats in that time too. I am feeling better now, but still feel my glands. 14 days after contact I went for a PCR/RNA blood test and yesterday I had the oral Rapid test done. Both came back negative. I know that I need to wait the full 3 months for these tests to be conclusive.
My question is this: If I DID start seroconverting 5 weeks ago, is there still a chance that the anitbody test of yesterday would come back negative. (I know that the official medical answer is probably yes, but I`m looking for some light in my freak outs).
Regarding testing for HIV infection, the PCR-based qualitative (not quantitative) assays are probably the most sensitive at determining early infection with HIV. However, they are not FDA-approved for the diagnosis of HIV infection. Only the antibody testing methods (e.g., serum/blood ELISA or EIA tests, or oral swabs) are FDA-approved for diagnosis. If positive, these antibody testing methods then require a confirmatory test before an HIV-positive status can be assigned; this confirmation process is usually part of the serum/blood testing algorithms, but for the oral swab testing, it requires an additional blood test to confirm a positive result.
Regarding seroconversion and testing, almost all persons will have seroconverted (by definition of a blood antibody test), by 6-months after the exposure, and most will probably have seroconverted by 3 months after the exposure. Any timing guidelines earlier than that for seroconversion are most likely to be a matter of the individual exposure and therefore much harder to predict. As noted, the exposure to blood during intercourse is a high risk for transmission if the blood comes from a partner who is HIV-infected. Despite being high risk, the active partner is likely to have a lesser chance of acquiring infection than the receptive partner; however, both do have risk of acquiring HIV infection.
Stephen Kralovic, MD
College of Medicine
University of Cincinnati