[Question #11415] Test Result Confusion

14 months ago

Hi,

thanks for your service. Around 15 months ago, I had oral sex with a transexual girl with some cum in mouth, did a 4th generation HIV test 22 days later , which was negative. I have been in a relationship since. Yesterday, I went to the clinic to get a HIV test ( I need it for my work visa, as I work overseas). I did the HIV/ Syphilis duo test 15-20 min duo test and the result was negative.

30 mins after I left the clinic, I received a call and was told a faint red line appeared on HIV line on the test (i was called 50 mins after the test was done) and asked to return to do a lab test. I returned and the doctor said a faint line appeared around 20-25 mins after doing the test. I did a 4th generation test, which was negative. He said it was probably a false positive but should do a lab test to confirm.

How worried should I be?

Thank you.

H. Hunter Handsfield, MD

14 months ago

Welcome to the forum. Thank you for your confidence in our services.

The rapid tests are inherently more subjective in interpretation than the lab based tests. That is, the lab-based antigen-antibody test (AgAb, i.e. 4th generation test) is automated and 100% reliable. That negative result proved that the weakly positive rapid test was false. You can be completely certain you do not have HIV. Whatever additional test the doctor has ordered will also be negative.

In addition, you describe a very low risk exposure 15 months ago. Oral sex is inherently low risk: I believe you mean your partner's semen was in your mouth. If so, and even if he had HIV, your risk of being infected was around one chance in 10,000. That's equivalent to giving BJs to infected males (your partner anatomically was male) once daily for 27 years before being infected might be likely.

So you can relax as you await the confirmatory test result. Feel free to let me know that result when you have it. In the meantime, I hope these comments are helpful.

HHH, MD

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14 months ago

Dear Hunter Handsfield,

Thank you for your reply. Maybe I was confused by the what the doctor said. The first test was blood from my finger. This was the one that showed a faint red line around 25 mins later. When i went back he did another test, where he drew blood from my arm, put some on a different test strip, waited 10-15 mins and it was negative; He said this type of test was more reliable than the first. I thought he said this was 4th gen. but maybe I misinterpreted this?

Then he said he would send the rest of the blood to a lab for testing. Would change your analysis?

Thank you.

H. Hunter Handsfield, MD

14 months ago

Thanks for the clarification. It doesn't change my evaluation. There are rapid 4th generation blood tests; I'm sure you can trust the doctor. When there has been a possible false positive test result, it is common to do more than one additional confirmatory test. You can expect the additional result to also be negative.---