HSV-1, Unprotected fellatio

Hi Doctor,
I’ve read about the risk of contracting STD’s to the male receiving partner involved in unprotected fellatio. It seems that this is generally considered safe although there is some small risk. As I’ve read, the highest risk involved to the male receiving partner is the transmission of HSV-1. This seems to be risky only when an oral outbreak is present on the giving partner. I know that oral herpes is common, as many web sources state. I am unsure why oral sex can be considered safe if oral herpes is so common.

1 How likely is it that oral herpes, among those who have it, is present in the population in the prodome or symptomatic stage?

If oral herpes was mostly at risk of being transmitted during the symptomatic stage then a preventative measure to acquiring it would be to check for signs of an HSV-1 on the partner prior to fellatio. I’ve read that oral herpes is almost exclusively found outside of the mouth, on or around the lips.

2 Is it most likely that oral herpes will be visible outside of the mouth, on or around the lips during an outbreak? Could it be present inside the lips, such as where the lip touches the gums?

I’ve read threads where males have contracted oral herpes during unprotected fellatio from HSV-1 positive partners but it was before an outbreak occurred on the partner. It may have eluded visual detection. So assuming HSV-1 is a relatively higher STD risk factor in unprotected fellatio and is mostly at risk of being contracted if a visible outbreak is present, I have general question about unprotected fellatio.

3 If the partner giving fellatio were to show no visible signs of oral herpes on the lips or outside of the mouth, would there be a near zero risk of contracting an STD during unprotected fellatio?

4 If HSV-1 were contracted due to unprotected fellatio would there be a single outbreak and then no subsequent outbreaks due to immunity, like chickenpox? Would there be lifelong outbreaks similar to HSV-2?

[H. Hunter Handsfield, M.D.]

To your questions, one by one.

"I am unsure why oral sex can be considered safe if oral herpes is so common."  Nobody said oral sex is risk free, and "safe" is relative.  Oral sex carries some risk, but for STDs in general it is much safer than vaginal or anal sex.

1) Half the US adult population has had HSV-1 and most such infections are oral, but at any point in time the proportion of the population having an outbreak--with or without symptoms--is very much lower.  As a guess, I might say one person in 1000, but no data exist and nobody knows the true answer.  You are correct that avoiding oral sex with someone with a sore on or near the mouth is an important strategy to prevent genital HSV-1.

2) You answered yourself in the previous question.  It is correct "that oral herpes is almost exclusively found outside of the mouth, on or around the lips".  (Technically, that applies only to recurrent oral herpes. The initial infection often includes sores inside the mouth, often with severe sore throat as well.)  Sores inside the lips usually are not herpes.

3) Usually the transmission risk is low in the circumstance you describe.  But "near zero" might be stating it too strongly.  There are too many unknown factors that can influence it.  For example, if the insertive partner has had HSV-1 (oral or anywhere else), he is immune or at least highly resistant to a new infection.

4) Symptomatic recurrences are much less frequent for genital HSV-1 than HSV-2.  About 40% of those with HSV-1 have no recurrences; another 40-50% have 1-2 recurrent outbreaks over the next 1-2 years, then nothing; and only a few percent have ongoing outbreaks.  Asymptomatic viral shedding has been less well studied but likely also is less frequent than for genital HSV-2.  (But even HSV-2 typically doesn't cause "lifelong" outbreaks.)

Regards--  HHH, MD

[Holden43]

I’ve searched the web and this is really a unique resource. Thank you for your time and patience. I’ve tried to format these questions so that they may be useful to other viewers. I have another issue that is more personal and specific. It involves another STD, however, so I’ve posted a new question.

-Holden

[tm4211]

A related discussion, HSV2 from fallatio ? was started.

[johndoe36]

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