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Source Negative, DNA PCR and PEP


Hi, Took PEP for 28 days. Source was negative at 29th day (DUO test and Proviral DNA Test). I am negative as of 68 days (DUO Test). I was tested negative on 7, 10, 21 and 45 th day using Proviral DNA and 51 days using PCR RNA test. Am i risk free now?



Thank you for your inquiry. From what we gather from the question, you were asking about the reliability of a DUO test at 68 days.

The DUO test (also known as 4th Generation EIA test), has a window period of 4-12 weeks. While most HIV specialists consider this "DUO" test conclusive at 6 weeks, official HIV testing guidelines still recommend re-testing at 12 weeks (84 days) for completely conclusive results. Accuracy of the DUO test is 99.9%, making it extremely unlikely that any of the test results you have received (Days: 45, 51 and 68) to be false negatives. This means that although you are technically required to re-test at 12 weeks for "completely" conclusive results, you can almost certainly rely on the validity of the multiple tests you have received within this time frame.

It was responsible of you to seek PEP as a biomedical alternative to protection when engaging in high risk activities. We would recommend you also explore other protective measures such as PrEP when engaging in high risk activities. Additional measures include barrier usage in sexual activity or clean needles for intravenous drug use.

Recommendation: In concordance of official HIV testing guidelines, please seek re-testing at 12 weeks for "completely conclusive results", but rest assured that your previous tests are reliable. Please also refer to a physician for other health related questions.


AIDS Vancouver Helpline/Online, Danielle