[Question #4528] Hiv rapid finger prick test

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81 months ago
Hello I took three rapid finger prick test Alere Determine AgAb at clinic. On 73 days 87 days and 103 days after exposure.  Do I need to test again or take a different  kind of test?  Or I'm I conclusive  with the resultsThank you
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H. Hunter Handsfield, MD
81 months ago
Welcome to the forum. Thanks for your confidence in our services and your succinct question.

All existing HIV AgAb (antigen-antibody) blood tests ("4th generation", "duo", "combo", etc) are conclusive by  6 weeks after the last possible exposure. This includes Determine® and other rapid, fingerstick tests. In other words, your 73 day test was conclusive, and could have been done a month earlier than it was. The tests at 87 and 103 days were unnecessary. (You might have been reading outdated information about 3 month testing windows. That was for older tests for antibody only. It's never necessary to wait that long with the AgAb tests.)

So all is well. You can move on with 100% confidence you did not catch HIV at the exposure you are concerned about.

I hope this information is helpful. Let me know if anything isn't clear.

HHH, MD
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81 months ago
Hello Dr.Handsfield, I'm  actually  a little confused  now. The people performing the finger prick test at the clinic  are the ones who informed  me that I needed to wait 90 days after exposure. Even if that is the case I did test at 103 days. I have read blood from vein is more accurate  then finger  prick. This has got me worried. Should I trust the rapid test and move on? Thank you
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H. Hunter Handsfield, MD
81 months ago
Lots of testing agencies and others continue to cite 90 days, either out of legal paranoia (their lawyers advise them to err on the long side) or because they just don't understand the science. All HIV/AIDS experts, and most public health agencies, give advice exactly like we do on this forum. It's also possible that Alere, the manufacturer, advises 90 days as conclusive for its own Determine® test. But even that doesn't mean it's necessary to wait that long. In developing a new test a manufacturer might only test people known to have been infected 90+ days. If so, regulatory agencies like the FDA, and FDA's counterparts in other countries, require they say that testing is conclusive after that time. It might be conclusive earlier, but they can't say it in the package insert, patient instructions, etc. They might say it privately, but not officially. But other experts are free to give science based advice that migth be different.

All blood tests, including the rapid fingerstick tests, are equally accurate. The other rapid test, using oral fluids (the Oraquick test) indeed is a little less reliable than the blood tests. But Determine® is equally good as a lab based blood test. You can be 100% confident in your own test results.

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81 months ago
Dr.handsfield, thank you with your expert knowledge. My main concern was a sore throat that lasted for several weeks after exposure.  I understand  that test results are what  we should have faith in but I must admit after searching  the internet  for weeks  there is a lot of outdated and false information  that brings anixety  and depression into every day lives . I was even told by my state AIDS hotline that 6 month testing is still required.     Thank you again.
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H. Hunter Handsfield, MD
81 months ago
The symptoms of ARS, including sore throat, are caused by the immune response to HIV, not the virus itself. That immune response is what makes the blood tests positive. Therefore, the blood tests (including the older standalone antibody tests) are always positive if HIV symptoms have been present more than a few days. So your negative test results prove that HIV is not a possible cause of any symptoms you have.* 

Any hotline or state health department advising a necessity to test as late as 6 months is just way beyond rational. Feel free to tell them I said so. (But don't be hard on the hotline staff. Most such jobs are minimum wage, with people trained to strictly follow scrpts they are given. It's their bosses' fault, not their own!)

That completes the two follow-up comments and replies included with each question, and so ends this thread. I hope the discussion has been helpful. Best wishes and stay safe.

* Here's another way to look at it.  Let's say you're exposed and 10 days later develop a sore throat and/or other symptoms common in ARS. A blood test is negative at 3 weeks. That result proves the symptoms are not due to HIV, and therefore would be reassuring, but it does not prove HIV infection is absent. An AgAb test still is needed at 6+ weeks to be sure that HIV (without symptoms) isn't present.

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