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