[Question #7847] HIV testing

51 months ago

Hi, apologies for my questions as im very confused.

Last year I tested for HIV after my partner cheated. I brought CE approved lateral flow self test kits in the UK which required a drop of blood from a finger to recieve a result in 15 mins. They came in a pack of 3 and I did all three of these tests at different intervals (all were done well after the 12 week window period). All three had a very faint positive line which I interpreted as weakly reactive. So I went to a GUM clinic and they did a 4th generation blood test from a vein in my arm and sent it off to a lab for testing. I recieved negative results from this. After receiving confusing advice from a clinician I went to another gum clinic and had another 4th generation blood test from a vein in my arm which was sent off for testing which also came back negative. At this clinic they also did a rapid finger prick test which came out negative.

Seeing as I intially had three positive self tests, do I need three 4th gen blood tests at a clinic to cancel out all three rapids or was just the first one 4th gen test at the clinic enough?

Also, was the testing that took place at the clinic (a fourth gen blood test) after having three positive rapid tests correct? Or did I need a whole series of different types of tests? For example I've read that western blots and pcr tests are used to confirm positive rapid test results, not just a single 4th gen blood test at a clinic?

51 months ago

I hope this doesn't count as a follow up, I just wanted to mention that I'm not too sure if my above question is too long or not, I counted less than 300 words but if you need me to rephrase please let me know

Edward W. Hook M.D.

51 months ago

Welcome to our forum and thanks for your question. I’m sorry to hear of the experience you had with your home tests. Those results however are superseded by your repeatedly negative 4th generation tests as well as the fingerstick test that you had in the clinic. Rapid tests which can be performed at home test only for HIV antibodies to selected HIV infections. These tests can be falsely positive in a small proportion of persons and may also falsely appear to be positive if the tests are observed for longer than the recommended time after beginning the test process. I do not have a good explanation for why your home tests appear to have been falsely positive. Laboratory-based fourth generation test test both for antibodies to HIV and the virus itself (theHIV antigen). These are amongst the most reliable tests in all of medicine and have a lower false positive rate then home tests. At this juncture I would encourage you to believe your clinic based negative tests and not worry further about the possibility of having acquired HIV from your previous partner.

I hope this information is helpful to you. If there are further questions or anything I have said is unclear please do not hesitate to use you were up to two follow-up questions for clarification. EWH

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51 months ago

Thank you for your response.

I think I read somewhere that when confirming positive screening/rapid results a different assay needs to be used, and this is what concerned me.

I also have recurrent/persistent thrush and this is why I worried about my HIV results. Is it common for people to have recurrent/persistent thrush for other reasons?

I usually test using a UK service called SH:24. Its a service where you collect 15 drops of blood from your finger into a microtainer and send it off for 4th gen testing at a lab. And a swab test for everything else.

Is this just as reliable as testing for STI's/HIV at a GUM clinic?

SH:24 has just upped the window period for HIV testing from 4 weeks to 7. Why might this be? Is this the new window period for 4th gen testing?

I don't plan on using rapid tests again, but for future reference are you saying that one negative 4th gen test at the GUM clinic or through SH:24 overrules any other result from other tests before?

I'm making sure to always use condoms from now on. I would feel more comfortable using condoms for oral sex too, but I know most people would find this a bit out of the norm. Do you have any advice for me in terms of my risks of getting STI's/HIV from oral sex? Or how to discuss using a condom for oral sex with a partner?

I am currently seeing someone. I have given him a hand job which I believe is safe sex. However afterwards, some of his semen was on a tissue which I then used to spit my chewing gum into. The semen on the tissue touched my mouth, is this a risk?

Edward W. Hook M.D.

51 months ago

Thanks for your follow up in the additional information. You are correct that positive test should be followed up with repeat testing. That said, your fourth generation repeat testing accomplishes that. I believe your test results.

While thrush is associated with advanced HIV, it is not typically associated with relatively recently (in the past year or two) acquired infections. In addition, most people with thrush do not have HIV. Some have other problems such as diabetes or have recently taken antibiotics. In some we don’t know why recurrences do occur but indeed that is the case..

approved fourth generation test provide quite reliable results. I would believe your results.

Regarding oral sex, the risk for acquiring HIV from performing oral sex on an infected partner is very very low, at least 10 times lower than from participating in unprotected genital contact. You are correct that masturbating a partner is a no risk procedure, Even when you get your partners general secretions on you in the process.. Similarly, the fact that your lips may have touched your partners ejaculate win disposing of your chewing gum is a no risk event.

Condom use during oral sex is not all that uncommon. I would hazard a guess that your partner would prefer to receive oral sex than not. Further, part of the reason condoms are not used more often is because they tend to interrupt the process of sexual activity. On the other hand, you can work to creatively incorporate applying the condom more pleasurably for both of you. I would encourage a discussion with your partner and some creative trial and error.

I hope these comments are helpful. EWH

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51 months ago

Ok thank you for all your advice, I think I'd be quite lost if this service wasn't available so I really appreciate it. I'll move on with my negative results, and maybe have a conversation with my current partner as well.

I'm not sure if you missed my questions about the SH:24 home sampling service, if you have any advice regarding the questions I asked please let me know.

But otherwise thank you for your help and for taking the time to answer my questions.

Edward W. Hook M.D.

51 months ago

I am sorry. I am not familiar with the SH:2b4 sampling service and cannot comment on it. I did look at their website and I am afraid it does not provide much information.

Most such sampling services work in close cooperation with well-established laboratories. If that is the practice of this service you can count on their results. I hope this helps. EWH

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