HSV Transmission Risk W/O condom

I am positive for HSV-2 for 20yrs. Previous partner of 15 yrs did not convert (to my knowledge) We shared a physician who was aware that we were discordant.  We abstained when I had an outbreak, but did not use a condom.   I have not had an outbreak in several years.  My new partner is is negative for all testable std's.  This female partner has potentially life threatening allergy to latex and some resins.  Currently, I am taking Valtrex 500mg daily.  What are chances and consequences of transmission in a long term relationship and what value does suppression therapy have in this situation?

[Edward W Hook, MD]

I presume your GF has had a good type specific blood test for HSV and is negative for HSV-2 and may or may not have HSV-1.  If she already has HSV-1 as do about 60% of adults, this may offer partial resistance to infection on her part through cross protective antibodies.

There are 3 different interventions proven to reduce HSV transmission.  These are consistent condom use, which your partner cannot tolerate, abstinence during outbreaks which you already do and chronic (daily) suppressive therapy with antiviral therapy which has been proven to reduce the risk of transmission by about 50%.  In the only major study of its kind, all participants were instructed to use condoms and to abstain during outbreaks and transmission occurred at a rate of about 8% per year.  The addition of valacyclovir reduce transmission rates to about 4% per year.  How well the group told to use condoms and abstinence during outbreaks followed instructions is unknown but it is reasonable to assume they were not perfect at this.  

We also know that despite having HSV for two decades, odds are that you still experience asymptomatic shedding of the virus some of the time.  That your prior partner did not appear to get the infection is in your favor but no guarantee that your new partner will not get infected.  Thus there is some risk to your partner although you are doing all of the right things. On a theoretical basis, there is better suppression of the virus with a 1.0 gram daily dose but this has not been studied.  Other than a slight increase in cost, there are no other adverse consequences to taking the higher dose for most people.

As long as your GF is aware that you have HSV and that you are doing the right things there is not too much else to do.  I hope this helps.  EWH