[Question #3808] Reassurance question regarding 4th generation hiv test results

35 months ago
Good afternoon Doctors,

 First, I would like to thank you for this service.  The internet is full of outdated and unreliable information on the topic of hiv testing, so this site, as well as the cdc webpage on current testing guidlines is a great help. 

 I am a 42 year old heterosexual male who slipped up and made a mistake back on April 2nd of this year.  I engaged in unprotected oral sex (analingus), both performed and received, briefly with a crossdresser whom I met on a dating website.   Since this encounter I felt regret for not using some type of protection or barrier.  There was no exchange of any body fluid, and no visible blood that I could remember.   We also communicated after the encounter and they specified that they were std and hiv negative.  I decided to get tested anyway just to be safe.  At 2 weeks post exposure I saw my doctor and he suggested a throat culture and blood test for syphilis, all of which came back negative and he said that everything should be fine.  Since then there have been no symptoms I feel confident that I am in the clear.

 I am knowledgeable enough to understand that Hiv is not typically not transmitted orally, and if it happened is was extremely rare or "only in theory".   However, I started to search the internet and began to worry.    So I got a 4th generation Hiv 01/02 ag/ab test (Labcorp) at 28 days post exposure which came back negative.  Additionally, after reading the cdc's recommendation on testing once again at least 45 days post exposure to rule out infection, I did get another 4th gen hiv 01/02 ag/ab test (Labcorp) at 46 days post exposure, which also came back negative.  

 Between the questions answered by the experts on this site, and the very recent updated cdc testing window period and guidelines I feel like  I am in the clear for Hiv as well.  However, I felt the need to get input from the expert physicians here to hopefully clear my mind and move on.   Would you consider my test results conclusive?

Thank you

H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
35 months ago
Welcome to the forum. Thanks for your question, and for doing substantial research on your concerns before asking. With one very minor exception, you got it all right.

There has never been a proved case of HIV transmission by oral sex, mouth to penis, and only a few in the other direction, i.e. penis to mouth/throat. Even here, if your partner had HIV, the average transmission risk was once calculated (by CDC) to be 1 in 10,000 if the penile partner had HIV. That's equivalent to giving BJs to infected men once daily for 27 years before catching HIV might be likely, and even that requires a) that the penile partner have HIV, b) that he not be on treatment for HIV, and c) ejaculation in the mouth. So this exposure was extremely low risk -- sufficiently low that testing was optional (recognizing of course that testing may still have value for reassurance).

As for test performance, you found exactly the right information. On this forum, we round off the definitive period for the Ag/Ab test ("4th generation") to 6 weeks, i.e. 3 days short of 45 days -- which undoubtedly makes no difference. We recently changed our advice from 4 to 6 weeks because of exactly the same report cited by CDC on their website. In any case, your negative result at 28 days was nearly conclusive and the 46 day result was 100% reliable.

So all is well and no need for further testing.

The "very minor exception" in your research:  oral-penile sex is fellatio, and oral-vaginal is cunnilingus. Analingus means oral-anal contact -- which, if I correctly understand your question, you didn't have.

I hope this information is helpful. Let me know if anything isn't clear.

HHH, MD

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35 months ago
Dr. Handsfield, 

Thanks very much for your reply and insight.  Your response regarding my hiv testing is very reasssuring, and If you believe no more testing is necessary, then I will move on from this experience.

Regarding my comment on analingus and my specific encounter. It indeed was oral to anal, I believe the term is also called rimming. From the research I did it seems as though this is a very low risk encounter as well.  

Thanks  for your expertise and advice. Once again, the service offered on this site is extremely helpful for those who need educated and reliable advice for some peace of mind and guidance. 

Thanks again! 








H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
35 months ago
Sorry I misunderstood the nature of the contact. However, it doesn't significantly change my response. Although specific data don't exist on HIV transmission risk through analingus (rimming), but what we know of HIV risks and oral exposure in general suggests little or no risk. By far the greatest risk from analingus is for various gastrointestinal infections for the oral partner.

Thanks for the kind words about our services. I'm glad to have helped. Let me know if anything remains unclear.
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35 months ago
Dr. Handsfield,

I appreciate your confirmation on the low risk nature of my exposure.  

Since I have one more question i would like your thoughts one last thing. During the last couple of months since my encounter of concern i have visited my own personal physician, as well as asked opinions on a couple of websites like just answer regarding hiv testing result recommendations.  Despite the avaialable data, current cdc guidlines, and the fact that specifically the 4th generation test has been available in the U.S. since 2010, many doctors still recommend to retest at 3 months “just to be sure”.   What is the reason for this?  The conflicting information undoubtedly is the reason for so many people having such high anxiety with the thought of having to wait so long for accurate results, even though this apparently isn’t necessary if 4th generation tests require only 6 weeks for definitive results. 

I would think that after 8+ years of 4th gen test here in the US, there would be a bit more awareness amongst Physicians and HCP’s, but this doesn’t seem to be the case.

I know there is no perfect answer for this question, but if possible I would like your opinion.  

Thanks, and take care.
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
35 months ago
This gets asked fairly frequently. There are no formal guidelines by CDC or most public health agencies that recommend a particular interval and to my knowledge no data exist on what proportion of physicians, clinics, etc advise testing at various intervals. For providers who still recommend 3 months as conclusive (sometimes even longer), I imagine some do it simply out of habit, since 3 months was the standard for so long. Others may not fully understand the newer tests. Still more may simply have a conservative perspective on such things -- and maybe there are even some who disapprove of their patients' sexual lifestyles and seek to encourage delayed resumption of behaviors they disapprove.

As you predicted, that's the third question and reply and so concludes this thread. I hope the discussion has been helpful. Best wishes and stay safe.
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