Q and A

Question

How accurate are finger-prick tests?

11 June 2010. Related: All topics, HIV testing, HIV transmission.

I had unprotected sex with an escort for no longer then 20 seconds then came to my senses and used a condom I have since been for a HIV antibody finger prick test 37 days after possible exposure which was negative and was wondering how accurate this test would be?

Answer

Answer: Charlotte Walker

Thank you for your question.

Finger prick tests are more than 99% accurate but this would depend on the type of test you used and what it is testing for. The OraQuick test, for example, is an antibody only test.

Test accuracy is also related to the window period. This is the time between exposure and the time at which point the test would be expected to detect a reaction.

For antibody tests the window is usually quoted as being a minimum of six weeks after exposure. Because 5% of people may take up to three months to develop antibodies, most guidelines recommend a confirmatory test after three months.

A negative test result at 37 days is good news but UK guidelines would still recommend confirming this at 90 days.

For more information on HIV testing please follow this link

13 comments

  1. Lisa Thorley •

    Hi Abdul,

    Please see Q1 here:

    https://i-base.info/qa/what-are-the-most-asked-questions

  2. Abdul •

    Can anyone tell me what time period does a finger prick test cover for example if I was to take one on the 16th May, what time period does it cover? If it covers 4 weeks would it be 16th April to 16 May?

  3. Lisa Thorley •

    Hi Dr JS.

    Thanks for sharing your experience with us. How are you doing now?

  4. Dr JS •

    I had a rapid test after experiencing symptoms that I assumed were seroconversion. The rapid test showed negative and the consultant at the hospital actually wrote me a letter to take to my GP saying something along the lines of “This needs further investigation as whatever is the issue, we’re certain it’s not HIV”.

    Two weeks later a blood sample that I’d insisted was taken on the same day and sent to the lab, showed positive results – with a HUGE viral load.

    So I have a justifiable scepticism of the rapid tests. My recommendation would be: if you’ve experienced symptoms similar to seroconversion, have both a rapid and lab test: but assume nothing between them. To be told that you’re HIV -ve then HIV +ve within a 2 week period is psychologically mindblowing.

  5. Lisa Thorley •

    Hi Vee,

    Please see question 5 here:

    https://i-base.info/qa/what-are-the-most-asked-questions

  6. Vee •

    I tested negative but my fiancee who I have been in a relationship with tested positive, how possible is that?

    The last test she did during an eye op came out negative and I believe her when she says she has never been unfaithful.

  7. Lisa Thorley •

    Hi Adson,

    It doesn’t matter what a persons blood group is. Therefore, yes a finger prick test will detect if someone is HIV positive even if there blood group is O.

  8. adson •

    can rapid finger prick test detect HIV in blood group o positive?

  9. Simon Collins •

    I think it would be more helpful for you to have these discussion with an HIV organisation in Indonesia and contacting the excellent Spirita organsiation would be able to talk with the experience and advice you are looking for. http://spiritia.or.id/

  10. Alita •

    Hello,

    I am from Indonesia. I am really interested in the finger prick test and would like to know more. We have an anonymous, online VCT service which has been running for over 3 years now but often we cannot deliver our services as many of our members live outside the areas where we have a co-operation agreement with laboratories. The finger prick test seems to offer a solution, but I need to know more about the mechanism involved. Is it possible, for example, for the members to send back to us their blood samples so we can analyze them and then reveal the results to them after they have gone through our online post-test counseling session. We don’t want our members to find out on their own, as we have to make sure that those with a positive result understand the implications and go through the care, support and treatment protocol. Indonesia is a big country, it may need a couple of days for the samples to get back to us if they are taken in a distant location.

    I look forward to hearing from you soon.

    Regards,
    Alita