[Question #7094] HSV Testing

7 months ago
July 5 I had an unprotected sexual encounter. I decided on July 14 to be safe and test for everything, I have no symptoms of anything. I did request herpes blood test. My HSV 2 IgG Type Spec came in at 1.56 the HSV IgG confirm test came up negative. From everything I'm reading IgG is more long term antibodies versus IgM being acute exposure, which seems like it would have been a past infection? Why is one negative and one positive? Could the testing be wrong? Can IgG antibodies be detected after 9 days? I'm losing tons of sleep over this any help is appreciated. 
Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
7 months ago
In some disease states, the igM does come up first and the IgG later, but with herpes, they come up at similar times AND the IgM is loaded with false positives.  The IgG is the one you want to pay attention to.  Your IgG is positive, but at a low level and there is about an 85% chance, at 1.5, that this is a false positive.  You did test very early after an unprotected encounter and I would recommend that you retest in about a month and see what direction the IgG is going.  And if at any time during that month you experience any genital lesions, you should have that promptly evaluated in person
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7 months ago
So there is a good chance it is a false positive? You said 85%? If you get tested earlier (2 weeks) does the level go up assuming you are positive? Or can it remains relatively the same? I also saw a response that the likelihood after one encounter is very slim? It seems tough to wait a month! 
Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
7 months ago
You could retest after 2 weeks but that won't be a final result unless it goes way higher.  I think there is an excellent chance that this is a false positive!

Terri
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