[Question #8918] Stupid question

38 months ago

Hello everyone,

I, f, had an unprotected sexual encounter to a guy i didn't know, about 2 years ago. Since im starting a new relationship, i got tested for hiv, at the end of May. I was tested with a hiv antibody test. It was negative.

My question is about this: i tested positive for covid19 with an antigen test on May 8. My hiv test appointment was on may 23. I took an antigentest for covid before the appointment and it was still positive. Is my negative hiv antibody test still conclusive? Can i be sure that i don't have hiv?

Thx for your time

H. Hunter Handsfield, MD

38 months ago

Greetings, welcome, and thanks for your question. The old cliche "there are no stupid questions" certainly applies here. This forum would be a shadow of itself if we rejected or didn't respect all pertinent questions!

Your question actually is an important one that directly or indirectly comes up very frequently on the forum. I'm going to take the opportunity for a more detailed reply than usual, which may be useful in responding to future questions as well as yours.

The HIV blood tests are among the most accurate and robust diagnostic tests ever developed, for any medical condition. Only an extreme minority of medical tests have the level of reliability as the HIV tests, with the single stipulation that sufficient time must have passed since exposure or infection for them to achieve that reliability. For the tests based only on detection of HIV antibody, that time is about 8 weeks or, for older antibody tests now rarely used, up to 3 months. Also, the oral fluids test (Oraquick®) has a low rate of false negative results, i.e. misses about 1-2% of infections even after 3 months, because there is a lot less antibody in crevicular fluid (i.e. seepage between gum and tooth) than in blood. The lab based blood tests in most common use, i.e. the antigen-antibody (AgAb, "4th generation", "combo" tests) are almost conclusive by 4 weeks 100% by 6 weeks.

In particular, there simply are NO documented medical conditions known to affect the reliability of a negative test result, aside from being done too soon after exposure. That includes any and all illnesses, infections, vaccines, drugs, or other factors that you might think of -- including COVID-19. You can find internet buzz about immunosuppressive drugs, cancer chemotherapy, biotin, and others: it's all false smoke and mirrors. A couple of exceptions have been reported: large amounts of the compound biotin, sometimes used as a health supplement, may interfere with testing -- but only in doses far higher than normal. Acute hepatitis C virus (HCV) infection may have a minor effect, but this is rare if it occurs at all. Finally, when someone takes anti-HIV drugs after exposure to HIV (i.e. post-exposure prophylaxis, or PEP), and if PEP doesn't work (e.g. started too late), the time to positive test results can be delayed. In that case, the window period to a conclusive result starts at the end of PEP treatment instead of at the time of exposure.

The bottom line is that you can be sure your negative HIV test is reliable and that you are not infected. Your positive COVID test made no difference. (In addition, a single heterosexual exposure to a partner of unknown status is very low risk to start, whether or not condom protected.) Don't worry about it!

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

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38 months ago

Hi dr Handsfield,

Thank you for your elaborate explanation.

I do have two questions.

1) While reading up on this forum about covid and hiv testing, i read that your collegue dr. Hook responded to a question about covid and hiv and said that covid could potentially cause a false positive result for hiv. I worried that maybe the reverse could also happen, that covid 19 and/or the SARS-CoV-2 virus can cause a false negative hiv result in a hiv antibody-only test. I can still fully trust my negative hiv result, even with my positive covid antigen test?

2) you mention a simultaneousely acquired hepatitis c and hiv infection. I read about this online as well and i wondered what the window period would be for an hiv antibody test of you had acquired hiv and hepatitis c at the same time?

H. Hunter Handsfield, MD

38 months ago

If I recall correctly, there may be a single report of a false positive HIV test results in someone with COVID. But false positive results occur from time to time anyway; it's rare, but it happens. Its occurrence in someone with COVID doesn't necessarily mean COVID was the reason. In any case, this is exactly the opposite as a false negative result, and I have seen no such reports, nor is there any obvious biologic or technological reason to suspect it.

HCV is only transmitted sexually via potentially traumatic anal sex practices among men having sex with men; and even here, almost exclusively in HIV positive men. So you were not at risk, should have zero worries about HCV, probably will never need to be tested. (Standard advice is that everybody should be tested, but only once, unless there are specific risk factors, like injection drug use, past transfusion, or other obvious blood exposure.) But in response to your question, even here there are only one or two reports of possible test interference, not nearly enough to calculate a numerical risk. Except that it's rare. A colleague of mine posted an online medical education comment about sexual transmission of HCV, and it also addresses why you also were at little or no risk of HIV: https://www.mdedge.com/familymedicine/article/255472/infectious-diseases/hepatitis-c-sti?channel=28225

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38 months ago

Hello doctor Handsfield,

Thank you. I got tested for hep c antibodies three months after the exposure and i also had an hiv antibody test at three months past exposure. Both tests were negative. I did notice some yellow in my eyes (i do drink too much) so i got scared that the hep c ab test was falsely negative. I read about the possibility of a delayed seroconversion if you contract hiv and active hep c at the same time. So i figured i had to do another hiv antibodytest at a later time. So two years later i get another hiv ab and hep c ab test and both are negative, but then it turns out my covid antigen test is still positive.

Could i have been sure that i was hiv negative at three months past exposure? with the negative hiv ab test and hep c ab test? Did i Just put myself through a lot more anxiety than was necessary?

Thank you and best wishes

H. Hunter Handsfield, MD

38 months ago

The answers to these additional questions were answered above: re-read my main reply above and concentrate on every word. It is 100% certain you you do not have HIV or hepatitis C.

That completes the two follow-up exchanges included with each question and so ends this thread. I hope the discussion has been helpful. Please do your best to stop worrying: you're fine!

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