Low positive HSV 2

[floridian25]

Hi Terri,

I have some concerns regarding a recent “diagnosis.”

On June 23rd I had a blood test during a physical, and for whatever reason, herpes was included in the regular std screening, which I now understand is rare.

Anyway my results were as follows.

HSV 1 IGG >5
HSV 2 IGG 1.5

My last possible exposure was on May 12th, however I was in a relationship and have only slept with this one person in the last year. Also, for the last month of our relationship, we were using condoms.

Anyway, I have seen on other questions that you estimate that with a number of 1.5 there is an 85% chance that it was a false positive. Can you please explain this to me? It seems odd to me that the testing company can get away with that – there must be many people with false diagnosis if this is the case no? I guess I just wanted to hear what you would estimate my chances of actually having hsv are?

Thank you!

[Terri Warren]

You are correct. There is an 85% chance that your result is a false positive.
Developing an antibody test is tricky – you want to have the cut off low enough that you capture all the infected people but high enough that you don’t have false positives. This test is a good test, but these false positive results can be devastating for people. In our hands (and we do this test in our office), 5.5% of people who test with the herpeselect ELISA test in the low positive range (1.1 to 3.5), which means that generally, the test is very accurate for HSV 2 in particular, in terms of false positives. But in my mind,, the thing that needs to happen is that these low positives need confirmation routinely, and honestly, there is no routine confirmatory test at this point that is easy, readily available and reliable. THAT is the problem. The best confirmatory test is herpes western blot but it is done only at the University of Washington and must be read by three experienced readers. that is not automated.

Your value needs a western blot confirmation. Our clinic can order that for you is you want us to help. It is not readily available otherwise.

Terri

[floridian25]

Ok thank you for the response.

Do you have any literature/ information that corroborates the 85% theory. Also I went to an id and he said it’s possible that my hsv1 triggered my hsv2 but said I still probably have it. How is it that he doesn’t know that I only have a 15 percent chance of actually having it?

Thank you! This forum has been extremely helpful to me.

[Terri Warren]

BMC Infect Dis. 2005 Oct 14;5:84.
Use of “biokit HSV-2 Rapid Assay” to improve the positive predictive value of Focus HerpeSelect HSV-2 ELISA.
Morrow RA1, Friedrich D, Meier A, Corey L.

This study has a nice chart answering the question that you pose.
My advice remains to obtain a herpes western blot for confirmation.

Terri

[floridian25]

Thanks for the info Terri.

I noticed that this article was published in 2005 however, wasnt an updated test released since then? Do you have any data from that one if that is the case?

I will definetly be obtaining the western blot test, however I do not want to get my hopes up.

Thank you!

[floridian25]

Also one other thing I am 23 years old.

You mentioned in another thread I believe that a low positive could just be indicative of a more recent infection. Because I am relatively young does that make it more likely that I just currently have a low index value?

Thanks!

[Terri Warren]

We have more recent data, but it has not yet been published but I will be presenting it at the ISSTDR meeting in Brisbane next month. It confirms the results from the Morrow study. The tests have not changed at all so there is really no reason to think any future study would be any different.

Age does not have anything to do with the likelihood of a false positive or not or the index value level.

Terri

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