[Question #1608] Questions about window periods, OraQuick

44 months ago
I had unprotected vaginal sex with a man probably a dozen times between early December and 12/19.
Before we did so, we each used an OraQuick oral swab test. They were both negative.  I was pretty unimpressed with the figure on the box stating that the test detected 91.7% of infections (later, of course, was when I felt concern over it). I don't believe this guy was doing anything risky for at least a few months beforehand. It's possible I suppose, but I'd be very surprised based on what I know of him.
But, I went ahead and did a full STD panel  with an HIV RNA test at 11 days after we stopped having sex (12/30), all of which were negative.

Would you consider that sufficient, in regards the HIV? Was that a bad day for OraQuick, or what? Should I feel free to carry on without fear of passing on HIV to someone else, or should I go back for one more? 
Also, I'm seeing some sources say that 4th gen tests are good after just 20+ days (ie, Dr Tan). Is that true? 

Thanks for your time.
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
44 months ago
Welcome to the forum. Thanks for your confidence in our services.

Before answering your questions, I'll comment that if your partner isn't at special risk for HIV -- i.e. not an injection drug user, doesn't have sex with men, not previously incarcerated, not an immigrant from an area where HIV is especially common like southern Africa -- the chance he has HIV is extremely low. In North America and western Europe, heterosexually transmitted HIV remains much less common than you might assume from media reports. That's not to say you shouldn't take precautions like rational partner selection and condoms with new or unknown partners. Since you are confident your partner has not been at high risk in the past few months, the chance you were infected is extremely low.

As for data on test performance, such as the oral fluids test (Oraquick) detecting only 91.7% of infections, those data generally understate true test performance. There are limitations in how the research on test performance is done, and the reliability of results. For example, patients in those research studies have made errors when they tested themselves. However, manufacturers must use the results from those studies in their package inserts, regardless of later data that may emerge. The real world performance of the oral fluids test is generally believed to be quite a bit better. It takes longer than the blood tests to become reliably positive -- 3 months for Oraquick but only 4-6 weeks for all blood tests -- but beyond 3 months a negative Oraquick test is considered conclusive.

The RNA blood test detects nearly all infections at 10-11 days, but still misses a few. That result probably was 90-95% reliable. I'm not familiar with Dr. Tan, but most experts consider 4th generation (antigen-antibody) blood tests conclusive at 4 weeks. It undoubtedly detects almost all infections at 20 days, but that's not the official advice from most authorities.

You don't mention other STDs. If not done, you would be wise to also be tested for gonorrhea, chlamydia, and syphilis. The chance of the first two is much higher than for HIV. Syphilis risk is just about as low as HIV, but it's a simple blood test and usually done reoutinely in anyone concerned about partner safety and being tested for HIV and STDs in general.

I hope this information has been helpful. Let me know if anything isn't clear. Best wishes and stay safe--   HHH, MD

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44 months ago
Thanks for the info. I did have a full panel of STD tests done, but will go again later to be sure. I also went ahead and waited the 28 days for the 4th gen HIV test and it came back negative. Thanks again!
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
44 months ago
Thanks for the feedback and glad to hear of your negative test results. Your HIV test result is conclusive. I see no need for repeating a "full" STD panel. The main thing is to have negative chlamydia and gonorrhea tests (by vaginal swab or urine) at any time, and negative syphilis at 6 weeks or more after exposure. In the absence of symptoms, I wouldn't recommend any other testing.

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