[Question #5616] Genital HSV 1

21 months ago
My female partner tested positive for HSV1 by IgG.  She recalls perianal blisters 3 years ago after sexual activity and given course of Valtrex.  There has been no outbreaks since.  I am negative for HSV.  Im a physician and have read up on this topic.  How do I protect myself from being infected,  as close to 100% as possible but still engage in intimacy, ie kissing, oral sex and protected intercourse.   Please address utility of PCR test, to exclude false positive.  And utility of daily Valtrex both for her as well as for me.  If you have a higher level of consultation,  ie phone call, Id be happy to pay for a consultation.  Thank you!
Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
21 months ago
We can do a video consult if you want to but let me answer what you ask here and then you can see if we need to do that. 
So was no swab testing done of her perianal lesions?  A positive HSV 1 antibody result alone cannot tell you where her infection is, only that she has it, if her IGG value is greater than 3.0.  If lower, she should obtain confirmatory antibody testing like the herpes western blot.
Let's assume for a moment that her lesions were herpes and she has HSV 1.  First, have you been tested to know that you are negative for HSV 1?  If not, it would be good to be tested to be sure your opinion is correct (and that you don't have HSV 2 and don't know it), and remember that the IgG misses 30% of HSV 1 infections.  There is no utility for you to take Valtrex, but if you are truly negative, it would be useful for her to take suppression daily - 500 mg Valtrex is appropriate. 
HSV 1 transmission is rare - none of the three of us responding here have seen a patient get HSV 1 genital infection who has NOT received oral sex.  Now that's not definitive, but it's pretty damn close.  If she only has it genitally, kiss away, by all means!
Let me know what other questions you may have.

Terri Warren
---
21 months ago
I dont know if a swab was done back in 2016, but will confirm.  Her Ab level is 2.8.  Is it possible to do a DNA PCR to see if there is any circulating virus?  We are both negative for HSV2 IgG and I am negative for HSV1 as well.  However,  Im interested in doing a more accurate test to exclude a false negative.  As youve said, positive antibody doesnt localize infection, but is it safe enough to just rely on her recollection that the only lesions were perianal?  Id imagine that HSV1 should have equal chance of transmission to genitals and mouth in an unrestricted sexual relationship.  And without knowing mouth status, receiving unprotected oral sex shouldnt be safe, no?  Much appreciated!
Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
21 months ago
Herpes is not in the blood stream so a PCR of the blood is completely inappropriate.  It is an infection of the nerve and skin.  PCR should be used for swab testing only and is far more sensitive than culture.  With an index value of 2.8, she may benefit from a confirmatory test.  With HSV 2, the CDC recommends confirmatory testing (western blot is best) for anyone with a positive index value below 3.5 as there are certainly false positives in that range.  With HSV 1, false positive are less likely but do happen.  HSV 1 genital infection is shed on about 5% of days swabbed (5 out of 100, for example) so it isn't very infectious.  HSV 1 orally in a person with recurrent cold sores sheds on about 25% of days.  HSV 1 prefers the mouth so it is possible that there is slightly more risk of oral infection, from giving oral sex, than transmission through intercourse, though we have no data on that - that's just speculation based on the site preferences of these two viruses. 

Terri
---