False positive HSV 2?

[confused94]

Dear Dr.

My recent test results for IgG testing for HSV 1 came back a 2.3 and HSV 2 a 1.9. Could this be a false positive for HSV 2?

When I was with a previous partner, I showed no symptoms what so ever. I was tested for HSV 1 and 2 about 4 1/2 months after my last contact with that partner. My test results were negative so can I rule him out completely as the person who could have infected me?

I was with my last partner about 10 months ago and a few days later that’s when I noticed a sore on my genitals. I went to the doctor and got tested for HSV 1 and 2 and it came back negative. This partner was tested for HSV 2 and came back negative. I don’t know if he was tested for HSV 1 though. Is it possible that since my last partner had performed oral sex that I may have contracted genital HSV1?

I’m confused and scared. It’s a shock to me that I tested positive and my last partner tested negative. Do you suggest I get retested? If so, what test do you recommend?

Thanks

[confused94]

Thank you so much for your response. I feel there is reason to hope now. I will get the Biokit done asap.

Thanks again

[H. Hunter Handsfield, M.D.]

Indeed there is a good chance your HSV-2 result is false positive, i.e. that you are not infected with HSV-2.  This issue has been discussed frequently on this forum.  Here is URL for the most comprehensive recent discussion:  http://www.medhelp.org/posts/show/593272

And here is the central statement from that thread:  "The manufacturer of the most commonly used HSV antibody test in the US (HerpeSelect brand, produced by Focus Technologies) submitted data to the us Food and Drug Administration that showed that results with ELISA ratio values over 1.1 were positive for HSV-2.  Later research showed that values between 1.1 and 3.5 often are false positive; the lower the value, the more likely the result is false, even though technically positive."

Further, a low-positive result like yours is especially likely to be false in someone who also has a positive result for HSV-1, as you do.  Taken together --  your positive HSV-1 test and HSV-2 ELISA ratio of 1.9, there's probably only a 20-30% chance you actually have HSV-2.

The other thread also describes the steps you can take to sort this out.  The simplest is to have another, standard HSV-2 antibody test from a different manufacturer.  The most convenient probably is the BiokitUSA test, which is done in 20 minutes in the provider's office.  Even if your doc doesn't routinely do that test, s/he can order a single test kit for you to be tested.  Alternatively, you could have the more expensive (and probably not insurance-covered) HSV Western blot test.  I suggest starting with Biokit.  You can expect a negative result, confirming you don't have HSV-2.

A final point is that, as you are learning, it probably wasn't a good idea to be tested in the first place.  Confusing results like yours are most common when someone is at low risk for having HSV-2 in the first place.  If you had symptoms of herpes or if your former partner was known to have HSV-2, testing would have been a good idea.  But your risk level was low to start.  But at this point you have to keep going with the additional testing, if you want to sort it out with certainty.

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