Herpes Questions (Transmission and anti-viral med questions)

[Questions101]

Dr,

You stated in an old thread "Finally, to put genital herpes transmission into perspective: Among monogamous couples in whom one person has genital HSV-2 infection and the other isn't, who do not use condoms, and who have sex at average frequency (3-4 times per week), there is only a 3-4% risk per year of herpes transmission. The risk for any single episode of sex, therefore, is very low."

1. I'm assuming this is without anti-viral therapy. Do you know the transmission rate for those on therapy?

2. "Per year," means that 3%-4% risk at year one becomes a 30%-40% risk at year 10? I'm trying to get clarification on what "per year" means. Meaning, is it compounded each year.

3. I always see the "4-6 outbreaks" for suppressive therapy used in literature as a recommendation for suppressive therapy helping reduce outbreaks/viral shedding, does this mean that therapy is less effective if you naturally have less outbreaks? I'm 30, contracted at 23, started out having about 4-6 outbreaks per year in various places in my genitalia. Now, without meds, I have them about 2 times per year pretty much at the exact same spot with much less severity. I'm considering therapy for reduction in transmission (the frequency of outbreaks really doesn't concern me as much as keeping my partner safe) but wondering how helpful suppressive therapy will be since I have less than the "4-6 outbreaks" they always speak of. I'm hoping and praying that my decrease in outbreaks, severity, and places on genitalia is an indication that I'm shedding less as time has progressed. So, hopefully coupled with suppressive therapy will decrease transmission rate. Your thoughts?


One more question, this one is actually for another couple that I know. So, it is unrelated to my first question.

If a man contracts ORAL HSV-2 from his partner that has Genital HSV-2. Does this decrease his risk of acquiring Genital HSV-2. Or is he still susceptible since he has it orally vs on his genitals?

[H. Hunter Handsfield, M.D.]

1) You correctly cite the data, which come from the research study that proved the effectivness of valacyclovir (Valtrex) in preventing transmission.  The rate in placebo-treated couples was reduced by half, i.e. 1-2% per year.  There are reasons to believe that's an underestimate, based on certain aspects of the design of the research study.  The actual protection rate probably is higher in most settings.

However, the actual risks in particular situations varies widely.  For example, most transmissions occur early in sexual relationships, whereas the research was done in couple who had been together for at least 6 months and often for many years.  Transmission risk also is much higher when the infected person has recently acquired herpes, but most in the study had been infected for a year or more.  On the other hand, there are circumstances when transmission rate clearly is less than 3-4% per year.  In other words, look at 3-4% per year as an average, but with a lot of variation around the average, so that statistic may or may not apply to you.

2) The data are not sufficiently precise to answer your question directly.  If anything, transmission risk declines with time, i.e. the opposite of a compounding risk.  That is, each year a couple goes without transmission, the likelihood probably diminishes.  So I doubt that transmission reaches 30-40% after 10 years.  But there really are no data; these are soft conclusions.

3) Supppressive therapy works just as well in people with less frequent recurrences, at least in terms of symptomatic outbreaks, and probably in preventing transmission as well.  In fact, it probably works better.  However, the FDA does not allow the formal indications, as stated in drugs' package inserts, to claim effectiveness in populations not studied.  All the research was done in people with 6+ recurrences per year.  All experts agree that the pros and cons of suppressive therapy, both in controlling outbreaks and preventing transmission, should be discussed and offered to all patients with genital herpes due to HSV-2, regardless of recurrence frequency.  Naturally, more people with many recurrences, and fewer people with fewer outbreaks, will choose to be on treatment.  But there are no hard and fast guidelines.

Bottom line:  If you ahve confirmed genital herpes due to HSV-2, and if you and your partner(s) decide preventing transmission is a high priority, antiviral therapy will help achieve that goal.  It's not 100% effective, but the combination of therapy, being alert to early symptoms and avoiding sex, and using condoms is highly effective in preventing transmisison, probably close to 100%.

I hope this helps.  Best wishes--  HHH, MD

[HHH,MD]

I didn't mean to blow off your closing question, no pun intended.  Once a person has HSV-1 or HSV-2 anywhere on his or her body, s/he is highly resistant (probably entirely immune) to getting a new infection with the same virus type, anywhere on the body.

HHH, MD

[Questions101]

Thank you Dr. I didn't realize that mose transmissions happen early in relationships.  What is considered "early."  My partner and I have been together for almost a year now. But I was just wondering what was considered "early?"

[H. Hunter Handsfield, M.D.]

There's no sharp dividing line, just a trend.  The highest risk appears to be in the first few months of a relationship, it probably tapers over several years.  The science on this isn't precise.

[gracefromHHP]

I encourage you and your partner to both take the time to read the herpes handbook at www.westoverheights.com. It has lots of useful information for the two of you to use so you can decide together what precautions you want to take to help reduce transmission.  If your partner is female - the risk of transmission is higher than if your partner is male and it's all covered in the handbook.

grace

[apollo13]

If you put Doc's answer about oral HSV2 immunity together with the quote below from www.herpes.com, you could have a natural and effective vaccine against genital herpes with very low risks of side effects.  So go ahead and rub your herpes on your partner's mouth.  

Here is the quote from http://www.herpes.com/hsv1-2.html:

"A third factor influencing the frequency of HSV -1 and 2 outbreaks is whether the virus is established in its site of preference. While HSV can infect both genital and oral areas, both types cause milder infections when they are away from "home" territory. Outside their site of preference, both type 1 and 2 lose most of their punch. . . .

Similarly, HSV-2 infection in theoral area-outside its site of preference-very rarely causes problems. First of all, oral, HSV-2 infections are rare, for reasons discussed below. But even when an infection occurs, recurrent outbreaks are uncommon. In one study (Lafferty et al., New England Journal of Medicine, 1987), oral HSV-2 recurred an average of 0.01 times a year in newly infected people. "I've never convincingly seen an oral type 2 recurrence," says Spruance.

[H. Hunter Handsfield, M.D.]

Nobody should intentionally seek an HSV infection of either type at any body site as a strategy to prevent other HSV infections.  I won't go into details; this has been discussed before.

HHH, MD