I had high risk exposure. I had sex with a women who hiv status is unknown on July 4 2019 I used a condom but it broke as soon as I realized I stopped. On august 10 2019 I(5 weeks) I got 4th gen test result was negative . Today October 1st(89 days from possible exposure) I went and got a alere determine Hiv-1/2 ag/ab combo finger prick. Also negative. My question is should I re test or can I be sure that I'm completely clean?
Thank you for your inquiry. From what we gather from the question, you were asking about the need to get a third diagnostic test. From the information given, this scenario is determined to be Low Risk (Evidence of transmission occurs through these activities when certain conditions are met) even though the activity that was performed (unprotected sex) is considered High Risk (There is evidence of transmission through these activities and are the majority of cases of transmission).
You are concerned that you received a "false-negative" result from the 3rd generation diagnostic test. This is very unlikely. For most accurate results, the "finger prick" test that you received should be taken 4 weeks to 3 months (although up to 95% of infections are detectable within 4-6 weeks) post-exposure. Most people develop detectable antibodies in 21-25 days (1).
Since you took this test within the proper window period, the accuracy of the test is extremely high (1). Official HIV guidelines recommend re-testing at approximately 12 weeks post-exposure, which you indicated having negative test results at 89 days (over 12 weeks) post-exposure. This would mean that your test results can be considered completely conclusive for this specific exposure.
Recommendation: No need for further HIV testing. Please refer to physician for other health related questions.
Regards, AIDS Vancouver Helpline/Online, Samantha