[Question #6875] Finger Prick HIV tests being inaccurate from Rice Univ one blood drop tests

64 months ago

I have had horrible OCD fears of HIV - I had an oral swab rapid test, (2) blood finger prick rapid test - and I am almost certain I had a test where they drew my blood for syphilis and tested me for HIV as well. All negative - all years after any risk factors I may have had (sex with female prostitutes always using a condom). I had finally overcome this fear for almost ten years – as these incidents happened in the early 2002 - 2006 time frame. I was never worrying about this until I came across this article about finger prick blood tests being possibly inaccurate from a study done at Rice University in 2015 - they tested hemoglobin, white blood cell counts, and platelet counts.

https://www.medicalbrief.co.za/archives/accuracy-of-finger-prick-blood-tests/

https://medicalxpress.com/news/2015-11-blood-results-vary-fingerprick.html

They said they were doing this because many more tests for blood work are moving towards fingerprick and not intravenous what scares me is does that mean the fingerprick HIV tests I took in 2013 & 2014 now could be inaccurate? That I could possibly be positive for HIV without knowing it? Like I also said I am almost 100% certain I also had an hiv test that was done from a blood draw and not a finger prick - but my anxiety and OCD is terrifying me that my HIV fingerprick tests could be inaccurate because using one drop of blood could give you and inaccurate result

H. Hunter Handsfield, MD

64 months ago

Welcome back to the forum.

I disagree that routine testing is moving toward fingerstick. Venous blood sent to the lab is still most common mode of HIV testing, as far as I know. Certainly there has been no change in test accuracy in the past few years. The fingerstick tests are considered by many to be slightly less sensitive that lab-based tests, but the difference is very small; and the difference between various brands of fingerstick tests also is small.

But you had almost no risk of HIV anyway. Even among the riskiest female sex workers in the US, well under 1% have HIV. Even without a condom, the average risk for a male partner having vaginal sex with an infected female averages 1 in 2,500. With a condom, it's 100x lower, 1 in 250,000. So even if the blood tests you had were "only" 99% reliable, your risk of having HIV is one in a few million. And if you had it for 10 years, you would be very ill by now, maybe dead. For all those reasons, there is no realistic chance you have HIV.

HHH, MD

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64 months ago

Thank you so much for answering today - I know you are one of the worlds foremost authorities on STDs. So in your opinion the fact that I had one oral swab, two fingersticks all negative - the accuracy of the fingersticks test that Rice U. spolke about in my case is irrelevant........also I also had a blood draw that went to the lab that was also negative (I believe they tested me with an RPR and HIV but can't remember for sure because it was ten years - and the fact that since its been almost 10-15 years since the incidents - then I am conclusively HIV negative even if I slept with multiple prostitutes (more than 30) always using a condom...I know this is just OCD and I am basically asking you the same question, but I am uncontrolble today as I am out of meds and can't get my anxiety med filled until next week......I am asking not to insult your intelligence but only because people with severe anxiety need reassurance and can't control themselves - your brilliance on these subjects is unquestioned. I'm sorry to ask for reassurance again........thank you for helping me

H. Hunter Handsfield, MD

64 months ago

Thanks for the thanks. I'm glad to have helped. Best wishes and stay safe!---

64 months ago

so I am definitively HIV negative - correct? No need to be tested again.............thanks for your help Dr.

64 months ago

My OCD kept at me tonight - There were some things I didn't understand in the articles I read so let me try to explain. The researchers at Rice were working on developing finger prick tests for anemia, platelet and WC counts and during testing they noticed their was wide difference between the first drop of blood and others ones (6th or 7th) giving divergent results; would this phenomenon only apply to those types of blood tests or could it also apply to HIV tests like the finger stick ones I took in 2012-2014; would the fact that my tests only took the first drop of blood cause my tests to be inaccurate or would the control on the test have been non-reactive if something happened in not collecting enough hemoglobin? That the first drop of blood for the HIV test could vary greatly from another one like what Rice found for their tests? Rice couldn't speculate on whether the discrepancies they found could would apply to other tests. Could this impact HIV rapid prick tests?

I also am almost certain I had a vein test at a lab which would make all this moot, but I still am scared bc I didn't understand if maybe this study could have exposed that many HIV rapid finger prick tests might not have 99% accuracy as thought of in the past - or is it just my ignorance that this wouldn't apply to HIV bc the testing approval process was incredibly rigorous. So sorry to be be a pain like this - my OCD can be incredibly debilitating, thank you for your kindness.

H. Hunter Handsfield, MD

64 months ago

I'm sorry, but this forum is not the place to address your OCD problems. Do your best to stop obsessing about the fingerprick tests. If you cannot, go ahead and have a lab based AgAb (4th generation) blood test. It will be negative. But my guess is you'll still come up with "what if" or "yes but" auestions. You need professional attention to your OCD; this forum is not the place for it.

That concludes this thread. Good luck.

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