Testing accuracy

[Bobby74]

Dear Doc,

My exposure was: receptive oral sex from a black female in Indiana.  I mention race and geography because I think the prevalence of HIV is low in Indiana. I put a condom on and inserted into her for 5 seconds, but the condom didn't feel right so I took it off and just let her finish the oral part.  Therefore, my only risk was from receiving the oral.  I understand from your posts that there have never been any cases from receiving oral sex via the oral to penile route.  Due to my anxiety I pursued a HIV Nucleic Acid Test that is used for blood donors, tissue donors, and deceased donors along with a 3rd generation antibody test.  The test was the Procleix HIV 1/HCV1 NAT test that used transcription mediated amplification with a sensitivity of 100 copies of the HIV virus/mL.  I have a couple of ?'s.  1.  Since this is a nucleic acid test, is 14 days post exposure accurate enough with a negative result since the company states that the window period is around 7 days due to the test being able to detect as low as 100copies/mL?  2.  Should I worry about HIV 2 since the NAT test only looked at HIV 1?  3.  The 3rd generation test did HIV 1/2, but this was at 14 days as well, what is the window period for a 3rd generation antibody test?  4.  If a person was infected with HIV at 14 days would they have way more than 100 copies/mL in their body and if so do you have an estimate of what amount?  5.  Do you think this test was a waste of money (because it was expensive) due to my near zero risk exposure?  Thanks

[Bobby74]

Thanks Doc.  That is very encouraging to me.  I guess I worry so much because my father passed away from AIDS when I was 12 in 1989.  One last question though:  Does the duration of the oral exposure matter, such as 1 minute opposed to 20 minutes or is it still a potential zero risk no matter what?  Thanks

[H. Hunter Handsfield, M.D.]

This is your fifth question on this forum in the past couple of years.  Except for one about your sister's potential workplace exposure to HIV, all have involved low to zero risk exposures and/or confirmation of common knowledge about HIV.  Once again, that's the case here.  You may continue to post such questions if you wish, as long as you adhere to the rule about a maximum of 2 questions every 6 months on MedHelp's professionally moderated forums.  But I have to question your judgment in doing so.

As for your other questions, the answers are obvious-- or you could have found them easily by simply scanning a few threads.  To start, there is little or no risk from receving oral sex.  To my knowledge, there has never been a proved case of oral to penile HIV transmission and some experts believe it never occurs.  So you were not at risk and require no testing on account of the exposure you describe, even if your partner happened to have HIV.  To the specific questions:

1,5) The negative results is good evidence you weren't infected, but a PCR test definitely was a ridiculous waste of money in this situation.

2) HIV-2 is too rare in the US to worry about.

3) This has been discussed innumerable times on this forum.  Around half of people with new HIV infections have positive results on "third generation" antibody tests; probably 95-100% by 6-8 weeks.

4) I don't know what levels of viral load to expect at 14 days in newly infected people.

HHH, MD