Transmission Rates for HSV-2

I recently tested positive for HSV-1 and HSV-2 with the HerpesSelect test.  I have never had an outbreak and I am not sure when I contacted the virus but it was not with my current partner.  I am involved in a long distance relationship where we have intercourse 8 to 10 times a year.  I am currently taking acyclovir to reduce transmission rates but I would like to know the following:

1) what are the chances if we don't use a condom that i could transmit and what are the chances if we do use a condom?
2) what if he performs cunnalingus?
3) Is acyclovir as effective as valtrex for reducing viral shedding?  I am taking acyclovir due to the lesser cost of it.
4) How soon or late will someone experience symptoms with a first encounter?
5)  How close to market is a vaccine?  I have read about a few clinical trials on the internet and that researchers have figured out how to activate the HSV-1  virus which then enables a drug to eradicate it.

[Edward W Hook, MD]

Welcome to the Forum.  The topic of herpes is a complex one.  The disease is common with HSV-1 being present in over 60% of adults and HSV-2 (the virus which causes most genital herpes) being present in about 1 in 5 Americans.  For both infections, the majority (about 90%) of people who have the infections are not aware that they are infected, either because they either acquired it without knowing in the past or because they misidentified their herpes as something else.  In your situation, it is impossible to be sure of the location of your infection however it is statistically most likely that the HSV-2 is a genital infection and that the HSV-1 is oral infection.   I will do my best to answer your questions but in general, many of these questions and information about herpes can be obtained by accessing excellent informational web sites such as the one run by the American Social Health Association (disclosure, Dr. Handsfield and I are both on the Board of Directors of ASHA).  Now, for your questions:

1.  Most exposures to infected partners do not lead to HSV transmission.  The rate of infection transmission  in monogamous couples in which one person has HSV and the other does not is about 8% per year.  There are 4 proven methods for reducing genital HSV-2 infection ( there are not good studies for HSV-1).  These are:  1.  To inform your sex partner of your infection, 2.  To avid sex during outbreaks, 3.  To consistently use condoms and 4.  To take antiviral therapy.  Of these, the best data are for the antiviral therapy which reduces transmission risk about 50%.  Condoms add to that reducing HSV transmission by about a third.

2.  In theory he could get HSV if you have genital infection with cunnilingus.  It is not well quantified but it is relatively uncommon.

3.  Only valacyclovir has been studied for prevention of HSV transmission but in the body valacyclovir is turned into acyclovir.  Acyclovir should work but, as you know, should be taken more often (at least twice a day rather than once)

4.  Typically symptoms of HSV appear 4-10 days after the transmission encounter.

5.  It is unknown if the vaccine currently being tested will work of not. The results of the current study should be available in 9-12 months.  After that, if it works, it could take another year or two to become available.

I would suggest your partner be tested for HSV.  There is a good chance that he is infected with one or both viruses already and the information from his test will help you in considering what precautions to take.  If he is infected, there is little to worry about in terms of transmssion.  EWH