Can a recent HSV1 infection provide a positive HSV2 result?

[WaRes]

Hi Terri,
I have had HSV1 since I was a child, resulting in intermittent cold sores only on my lip or under my nose, throughout my life (I am 47). I have never had any genital herpes symptoms or outbreak. I recently got divorced and wanted to get a full health check up including an STD panel (just in case my ex didn’t tell me something I should know). My IgG test results came back with a slightly elevated HSV2 result and my doctor thought there could be a crossover positive result because I had had a recent blister on my lip. He suggested I take it again. The second test came back BARELY above the positive threshold and my doctor is now suggesting I take the Western Blot test to be sure. I am not sure spending the money on the Western Blot (which is expensive) will really tell me anything I can’t already get confirmed from these results (below):

My questions are:
1) is it possible to have a slightly positive IgG HSV 2 result caused by a recent HSV 1 outbreak?
2) if it is possible could the same result come from the Western Blot, thereby not providing me a definitive answer?
3) Given my results (below), what would be your conclusion and would you suggest I get the Western Blot test done (~$300)?

Thank you!!

These were my results:

First Test Results Oct 2013
HSV 1 IgG 7.65
HSV 2 IgG 1.66

Second Test Results Sep 2014
HSV 1 IgG 5.56
HSV 2 IgG 1.18

These tests were performed with HERPESELECT HSV Type
Specific assays that utilize HSV I Glycoprotein gG 1 or HSV II gG2
recombinant antigens.

[Terri Warren]

So I would bet probably $500 that your HSV 2 result is a false positive result. At the level of both of these results, the odds are greater than 75% that it is a false positive. You have a wise physician. Except that having a sore on your lip at the time of the draw really isn’t the issue. The issue is that there is a slight crossover effect, for some people, at these low positive ranges, for people in particular who have HSV 1 infection already. The odds are definitely on your side here. Having said that, you may or may not be happy with those statistics. I have certainly seen people be both really negative (by western blot), really positive (by western blot) and I have seen people in this situation having an indeterminate western blot.

So how do you decide what to do? I can tell you that if this was MY IgG result, I would definitely do the western blot. So either it’s a false positive and you are incredibly relieved or it is a true positive which would be a bummer, but eventually, you would come to terms with this and live your live, or, in my mind the most troubling, an indeterminate western blot. This means that they cannot tell you for certain if you are positive or negative. This would be the hardest for me. But in people with low positive results on their ELISA, still, the majority of people have a clear positive or negative.

So in summary, I would advise the western blot. We order this test for all low positive patients and no one has ever paid that much. I think the patients for whom we order this test pay about $170. Also, do you have insurance? They should pay at least part of it, no?

Terri

[WaRes]

Hi Terri,
Thank you very much for your response. It provided me hope yet it seems you may owe me $500… ha ha 😉 I had the Western Blot done and I received the following response from my Dr.:

HSV WB Source Serum
HSV WB Result SEE COMMENTS
Positive for antibody to HSV-1 and HSV-2 by Western blot.
HSV WB Interp SEE COMMENTS
Evidence of past infection with both HSV-1 and HSV-2.
This test was developed and its performance characteristics
determined by UW Medicine, Department of Laboratory Medicine. It has
not been cleared or approved by the U.S. Food and Drug

I’m assuming that a “positive” is a positive. I’m unsure if there is an actual level or numerical result provided from the test? Is there any follow up question I should ask my doctor about the test or it is what it is?

Lastly, if it is what it is, and I’ve never had any sort of genetal outbreak, should I be looking for an outbreak anywhere else? Could it be that a cold sore, which I think is HSV 1 actually be HSV 2? Anything else I should be on the look out for given I’ve only had cold sores or a blister under my nose?

Thank you again, your help is greatly appreciated!!

[Terri Warren]

Yes a positive is a positive. There is no numeric value associated with a western blot.
Statistically, the chances were very small that this would be a positive, but the reason I wanted you to get the confirmatory test was because there is a small chance that it could be a true positive, and in your case, it was. I’m sorry.
Since you have both HSV 1 and HSV 2, I think that the cold sores you have are due to HSV 1 and statistically, the odds are that you have the HSV 2 genitally, even though you have no symptoms. The person who has HSV 1 is more likely to not have symptoms if they acquire HSV 2. I think that eventually, you will likely recognize a genital outbreak.
Should you begin to have sex with someone who tests negative for HSV 2, it would be good for you to be on daily suppressive therapy to reduce the risk of infecting the other person.
You’ve got one more question – is there anything else I can answer for you?

Terri

[WaRes]

Thank you Terri,
The only thing I can think of is to confirm that the only way to infect someone else is if you’re intimate while you have an outbreak. Is that correct? So the fact that I didn’t know AND I didn’t have any outbreak, I haven’t infected anyone. Would that be a safe assumption?

Thank you again,
I appreciate your help

[Terri Warren]

Unfortunately, that is not true. People can shed (give off) virus even when they have no symptoms. In fact, 70% of new infections are caused by people who show no symptoms at the time transmission occurred. That is why daily antiviral therapy is helpful in reducing transmission. People who have outbreaks have somewhat more frequent shedding days, but those are days that they can avoid having sex, knowing what is going on and understanding that is a day of infectiousness. If you would like to do more reading, I would suggest The Herpes Handbook, free on this website, or for more in depth information, The Good News About the Bad News.

Terri

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