HSV 1&2 Results, need help interpreting

[SlightlyWorried777]

Recently got back lab results from an STD panel and my doctor had his lab person call to tell me I was positive for both HSV type 1 (which I had expected, had a large cold sore on my lip 1 month prior to the test, as well as several times in the past), and also for HSV type 2. I was quite startled by the second result, being that my girlfriend of 5 months tested negative 3 months into our relationship (2 months ago). It was only after this fact that we decided to have unprotected sex. Myself, I had gotten tested post my prior girlfriend and was negative. I had three or four sexual encounters with a girl I had dated for a short period of time before dating my current girlfriend (in between girlfriends), but always wore protection.

Anyways, the lab results are as follows:
HSV type 1 : 0.91
HSV type 2: 0.91

Please help me in interpreting these findings. Thanks!

[Edward W Hook, MD]

I would not have recommended HSV testing for her (or for you) unless there was some risk of infection.  As I explained above, there is a higher risk of a false positive when you test in that way.  As I said, the IgM results should be ignored.  EWH

[SlightlyWorried777]

Thanks so much. However I did find out some disconcerning news today. My girlfriend called to verify her STD results from 2 months ago and they informed her that she had not, after all, been tested for HSV.  Now I am worried the high IgM might represent a new infection? I am not jumping to conclusions, just worried. I guess I am hoping it was due to the cold sore spell, and not something new brewing....

Again, looking forward to hearing from you..

[Edward W Hook, MD]

Ah!  This is very helpful and clarifies things.  The important tests, your IgG tests are negative - you do not have antibodies to HSV-2 or, for that matter HSV-1.  Your IgM test results are, frankly, irrelevant - IgM tests are inherently unreliable should be ignored.  there is no evidenc whatsoever that you have HSV-2.  

As to why your HSV-1 IgG test was negative is a bit unclear.  If this was your first cold sore a month ago, you may not have developed antibodies yet.  Alternatively, what you though was a cold sore might have been something else ( a canker sore, some other virus, etc)

I hope this comment is helpful. EWH

[SlightlyWorried777]

Thank you so much for your response. The test that I believe was performed was the Capita Herpes test conducted by LabCorp (only by means of deduction on other posts I had read, called and the lab tech and she didn't know).

Anyways, I just got a hold of the official results today and there are several differences to what I heard over the phone and what I reported yesterday. I suppose the medical assistant that was reporting the results wasn't entirely familiar with how to read the lab results correctly.

The actual results are as follows:
HSV 1 IgG         <0.91
HSV 2 IgG         <0.91

HSV, IgM I/II Combination           1.49  *HIGH*

So it appears that the medical assistant was in fact reading the IgG values (minus the less than sign) instead of the HSV IgM I/II Combination value.

This being the case what am I looking at? Could this high IgM value be due to the large outbreak of what I assumed was HSV 1 on my lip exactly 1 month prior?

Look forward to your response.  

[Edward W Hook, MD]

Welcome to the Forum. I'll be pleased to help you sort this out and will start by telling you that I am skeptical of that your result was a truly positive test for HSV-2.  Before I can provide a lot more detail however, several questions which are quite important for interpreting your results.  First, what was the brand (not the name of the lab where the test was performed) of test done- the Focus HerpeSelect and Captia Herpes tests are widely done, reliable tests, others are less so; second, was your test an "IgG type specific test" - some tests are not type specific and are terribly unreliable; and finally, did the results get posted as 0.91 or were there a  sign or other numbers.  The reason for the latter question is that these are quite low values and typically truly positive test results give higher values of >3.5.

Finally, a passing comment while you seek the information I have requested.  Even the very good IgG, type specific tests give results that are mostly falsely positive when positive in their low range.  If your HSV-2 result was really 0.91, it is just barely positve and there is, statistically, a greater than 80% chance that result you have is falsely positive, particularly since you have never had a typical genital herpes outbreak and since you already have HSV-1 (cold sores) both of which commonly lead to falsely positive test results.  

I look forward to hearing more information from you. EWH