HSV-2 IGG 8.2 False Positive!?

[andyvandough]

Recently my 36 y/o GF (of 8 months) and I did full STD test panel (“just to be sure”) as we both had had unprotected sex with multiple partners. We started having unprotected sex in April 2015 but (stupidly) we didn’t get tested until last month. I was tested on 9/14 and everything was negative (phew). She got tested and her results on 9/30 were *positive* for HSV-2! It was an IGG test and her value was 8.2. We were both very upset and had read so much about IGG having high positive rates albeit at much lower values (e.g. <= 3.5). My GF has never had any symptoms, though a few times in the last year she has had swollen lymph nodes in her groin area (which I know is a less common HSV-2 symptom).

We are almost ready to accept this diagnosis and deal with it but something just didn’t sit right and we pushed for further testing…her Dr. suggested doing a PCR test on both a blood sample and a vaginal swap…that was done on Thurs last week and we just got the result back an hour ago: NEGATIVE on both!

Our understanding is that the PCR test is much more specific than IGG (from what we understand it actually tests for the DNS of the virus) and has a much lower false positive / false negative rate. So should we now trust the PCR test and/or should we do any further confirming test?

The are going to redo the IGG test on the original blood sample (which they still have)…perhaps either the person doing the blood draw or the lab screwed something up….we’ll see.

From what I understood the IGG FP rate at such a high value should be extremely low? Are we missing something here?

Another note: My GF *did* get a shingles vaccine about 2 years ago..not sure if that could be a factor?

[Terri Warren]

I do understand your desire to do confirmatory testing though I seriously doubt if that was her blood the first time that things will change much.
Unfortunately, your doctor is ill informed about the technicalities of herpes testing. PCR is NOT done from blood. People with herpes do not have this in their blood stream, it is a disease of the skin and nerves. Also, it is rather pointless to do a genital swab when there are no lesions present. The odds of hitting a day of viral shedding with a blind swab and no lesion are very small. I really hate to burst your balloon but neither of those test results are useful in determining if she really has herpes or not. The appropriate confirmatory test is a herpes western blot antibody test. If you want this testing done we can arrange that for you. It is not a test that is available in any way except through us- we would send you to a lab near where you live for a blood draw and the lab will ship it to the University of Washington – or you can order a test kit from UW directly which you would take to your doc to draw blood and then they would need to ship it back to UW. Either way works. However, I must tell you that it is really unlikely assuming not blood mix ups, that she is going to be negative. I think it is a good idea to redraw the blood and the IGG test, just to eliminate sample switching somewhere.

Ideally, she would go on daily suppression to reduce the risk of infecting you, if the blood test is again positive.

Terri

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