[Question #10926] HIV Risk

18 months ago

Hello Doctors, I hope all is well. I had vaginal sex with a woman roughly 6 weeks ago with a condom but it was kind of half off my penis but it covered my head and some more. I took one single dose of PEP the next day that I had left over from one incident because I planned on getting a prescription again but I didn’t. I took an HIV RNA tests at 10 days and it came back non reactive. I heard they’re very accurate at 10 days but I’m not sure if I should trust my results. I would like to know the following:

1. Was this a risk for HIV to begin with since the head was covered? I’ve heard some people say that this is a no risk whatsoever event and I’ve heard other sources say while possible it is really u likely.

2. How accurate was my HIV RNA test since I took one dose of PEP? Will the PEP heavily skew my test accuracy?

3. My mother tested positive for COVID and then I did a few days later. COVID symptoms started about 35 days later and lasted for about 24-36 hours. Is it possible that the Covid test picked up HIV because I’ve heard of the opposite happening and the Covid symptoms were ARS? Is it possible to get ARS symptoms at day 35?

4. With all that was said including the HIV RNA test what are my odds of having HIV at this point in time?

5. Is it true HIV RNA tests are 98.2% accurate at 10 days? It’s a stat I saw online from a company in the UK that sells HIV RNA tests.

Thank you all.

H. Hunter Handsfield, MD

18 months ago

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

The quick reply is that condom protection against HIV is considered complete as long as the penile head and meatus (urethral opening) are covered. Also, if you're in an industrialized country, especially North America or Western Europe, the chance your partner has HIV probably is very low, probably under 1% chance -- although of course that depends on details you don't provide or might not know. Still, all in all a low risk exposure; I'm glad you didn't pursue PEP. The HIV RNA test probably would detect about 90% of new infection at 10 days, so that negative result is very reassuring but not conclusive. All in all, there is little chance you have HIV. To your numbered questions:

1. While I cannot quite endorse "no risk whatsoever", it comes close. See comments above.

2,5. See above -- around 90-95%. A single dose of anti-HIV drugs is not likely to negate or delay a reliable result. The particular figures provided by test manufacturers are based on data they submitted to the appropriate regulatory agency (FDA in the United States, comparable outfits elsewhere). I'm surprised by 98%; and without getting into the statistical weeds, depending on the number of patients analyzed to come up with that figure, the range of possibility might be something like 90-100%. That is, very reassuring but not conclusive.

3. Don't confuse symptoms with test results. Indeed both COVID-19 and ARS have many symptoms in common. Almost ALL human infections have several symptoms in common with COVID. But symptoms are a totally unreliable indicator either for or against ARS anyway; only test results matter in judging whether or not someone has HIV. And no, ARS symptoms typically start 1-2 weeks after exposure, rarely later and certainly not at 5 weeks.

4. Considering the exposure plus your RNA test result, the chance you have HIV probably is well under one chance in a million.

Have an HIV AgAb (4th generation) blood test, which is 100% conclusive by 6 weeks -- and you're there. You definitely can expect another negative result.

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

HHH, MD

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18 months ago

Hello some details that you said I failed to mention that may aid you further in your risk assessment are the following: me and her are both 23 year olds living in the Midwest of the United States. The 98.2% statistic was found by googling “hiv rna accuracy 10 days” and I was shown webpage by a UK company selling HIV RNA tests called better2know. The lab I got my HIV RNA test from was Quest Labs through STDCHECK.com which states their HIV RNA tests are 95-99% accurate at 9-11 days post exposure, which is an odd stat.

1. Have you, your colleagues, or anyone you know of who may be working in the field of STDs seen someone test negative at 10 days on an HIV RNA test and come back and test positive later? I know you all say that with the 4th gen test for the 4 week accuracy, I was wondering if similarly can be said about the RNA tests and coming and getting a 4th gen later.

2. Is additional testing even necessary if the odds are so slim to none at this point? From what I understand 1/2500 exposures will result in infection, something like 1/800 women have hiv in the US, condoms are 80% effective on the low end, and my hiv rna test is 90% accurate on the low end. Do the math odds are 1/100million I believe.

3. Is me recovering from Covid in 1 and a half days (didn’t even get a fever, just a stuffy nose and sore throat) a good sign since HIV causes immune deficiency, wouldn't most individuals get very ill with a coinfection especially in early stages of hiv?

4. What would your personal odds be?

5. I got paranoid about syphillis as well and I know a chancre appears after syphillis infection. I inspected my body for weeks after seeing if a chancre would show up and nothing showed up on my penis or mouth. Is it possible to get it on your anus if you didn’t do anything anally?

H. Hunter Handsfield, MD

18 months ago

1. No, this is extremely rare and I am aware of no such cases. But I still would go with 90-95% reliability of a negative result at 10 days.

2,4. Honestly you didn't need testing at all, in my opinion. It's your decision whether to have another test, not mine. I've given you my guesstimate that the chance you have HIV is under 1 in a million and your math also is justifiable; I could also endorse 1 in 100M. If you're OK with these odds, I see no need for another test.

3. Your covid recovery and symptoms make no difference at all. For certain kinds of infections, like TB or fungal infections, HIV can make a big difference. Usually not with garden variety day to day viruses, pneumonia, etc. The immune response to such infections is not much different in people with or without HIV.

5. Syphilitic chancres can only appear at directly exposed sites. And the chance a partner like yours has syphilis is almost as low as for HIV, maybe even lower.

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18 months ago

Hello thank you for the reply I just have a few more questions regarding my exposure and for further knowledge.

1. How effective would you say condoms are overall at protecting one from HIV? There is a lot of different numbers online.

2. Should I consider getting tested for syphilis if I didn't notice any chancres on my penis? I did have something that resembled a canker sore on my gums, but I do get those often I also did not perform oral sex.

3. Do condoms help with syphilis at all? I read they do not prevent it.

4. Anything else I should be concerned for?

H. Hunter Handsfield, MD

18 months ago

1,3. A properly used condom that doesn't break is nearly 100% protective against HIV. They're inherently less effective for those infections transmitted by skin-skin contacts, including syphilis, than for those transmitted by fluids like HIV. Different numbers on condom effectiveness often result from confusion between biological effectiveness (as just stated) and "use effectiveness", which takes into account user error, breakage, etc. All in all you can consider a properly used condom to be 100% protective against for any single vaginal or anal sex exposure, but people who only use condoms for HIV prevention have roughly 90% protection over time. The figures are similar for condoms as contraception. For syphilis, the percentages probably aren't quite this high -- but still highly protective.

2. On one hand, it's always good to have a low threshold for syphilis testing because syphilis is so dangerous and so easily treated and diagnosed. OTOH, your risk after this event is near zero. So it's up to you.

4. Comprehensive STI testing usually includes urine for gonorrhea and chlamydia, as well as blood tests for HIV and syphilis. The risk is low but testing is easy, so why not?

That completes the two follow-ups included with each question and so ends this thread. I hope the discussion has been educational and otherwise helpful. Best wishes and stay safe.

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