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Can you please confirm the 4th Generation window period is 12 weeks or 13 weeks or 90 days? Peel Health from Ontario says 12th week is conclusive. catie.ca do mention 4th generation is 99% accurate at 6 weeks, however, it doesn't seem like from the previous post from this forum (as I read from last post 6 weeks - 95% and 3 months 99%). My exposure was protected oral sex (receiver), again as per this site its no risk (even without protection for the receiver), however health nurse from Peel health hospital doesn't agree with this. (Maybe I haven't understood it correctly) HIV test done at 67 days is non-reactive and did another at 88 days (waiting for results). I wanted to make sure I am doing a test at the correct time and can move forward.


Thanks for writing.

You are correct that receiving oral sex (without or without protection) is not a risk factor for HIV. If the protected oral sex was your only risk for HIV we would not recommend testing based on that risk.

HIV is passed when blood and/or sexual fluids enter into a person's body (ie. inside the vagina, anus, or penis). For HIV to be passed to someone while receiving oral sex, there would have to be significant blood in their partner's saliva. Small amounts of blood will be diluted by the saliva in the mouth, and there is not enough virus to actually pass HIV. We do not see HIV being passed through receiving oral sex.

Regarding your HIV testing: The 4th generation HVI test is considered to be 95% accurate at 6 weeks, and 99%+ accurate after 12 weeks. There is no difference in accuracy if someone tests at 12 weeks (84 days), 90 days or 3 months. The reason some places say 90 days or 3 months is for convenience, people may remember this easier that 84 days or even 12 weeks. Your test at 67 days would be considered very accurate, and your test at 88 days will be conclusive.

Hope this helps. Please feel free to post a comment below or submit another question.

Health Nurse

This answer was posted on November 15, 2018

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