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How definitive is the IgG blood test?

ont
How definitive is the IgG blood test?

My doctor said it's not definitive/conclusive, but I tested negative for HSV2 IgG (result didn't specify the indication level) 8+ weeks after initial diagnosis, 10+ weeks after possible initial exposure and was wondering what conclusions to actually draw.

Reading http://www.biokitusa.com/NCCLS_BK_HSV-2_Whole_Bood.pdf it seems like it's in the 85%-95% ranges, but I'm not fully clear on how to interpret sensitivity and specificity (I guess I should look at the sensitivity since I'm concerned about a false negative).

Background: Had unprotected sex w girlfriend, 2 weeks later got what looked like zits on my shaft underneath the foreskin, went to the doctor, doctor says it's herpes but the presumed vescicles don't really have any liquid in them, nor do they ulcerate and crust (and the virus culture came back negative, as the doc said to expect).

About two months later I go back for a blood test, which comes back negative, but the doc says it's not conclusive - "it'll tell you if you have it, but won't tell you if you don't" kind of thing.

I haven't had any more outbreaks, but I'm obviously concerned about my health and what to tell future partners.

Is there any other test I should have done to get a conclusive diagnosis?

Thanks!
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Avatar universal
If the antibodies fall low then a Dna test is good for finding them after 6 months
Helpful - 0
101028 tn?1419603004
It leaves you with a lot of anxiety for not a lot of good reason. If your last negative result was 6 months after the last time you had sex with anyone, there's absolutely no reason for any continued testing. if it was only 2 months since the last time you had sex, then repeat it in 2 months as I already suggested.  

grace
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Avatar universal
ont
Reading the biokit PDF document, it says some confusing things on p6:

"The biokitHSV-2 Rapid Test detects antibodies to HSV-2 glycoprotein G (gG2)" ... blablabla ... "antibodies to this protein as detected by EIA or Western blot, may not be produced for up to 6 months after acquisition of HSV-2."

"Seroconversion can vary anywhere between 21 to 40 days"

"the median time detection of HSV-2 antibodies by the biokitHSV-2 Rapid Test was 13 days"

"HSV-2 specific antibodies usually appear in patient serum within a week of infection reaching peak levels in 4 to 6 weeks"


So far it seems like the test should be definitive at six _weeks_ - the six _month_ figure seem to apply to something slightly different. However, there's also the ever-so-reassuring disclaimer further down on that page:

"Some patients may not develop detectable antibody titers after infection and in others; antibody levels may fall to very low or undetectable amounts"

"the lack of antibodies to HSV-2 does not exclude the possibility that the individual is infected with HSV-2."

So where does that leave us?


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101028 tn?1419603004
4 months post encounter is conclusive for the vast majority of people.  Testing at 6 months is absolutely conclusive.

grace
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Avatar universal
Blood tests aren't conclusive at 8 weeks, but when are they? I had a blood test for each one of the herpes virus types, IgG , and it's been 6 months after my encounter. will that be conclusive?
Helpful - 0
101028 tn?1419603004
Has your gf been tested yet for herpes to know her own status?

really your symptoms don't sound like they were due to herpes and I'd doubt them unless your gf tests + on her test.  Should they reoccur, be seen for them and insist on a lesion culture of them.

A blood test at 8 weeks post symptoms isn't conclusive yet. Your gf getting tested will help you figure out if you even need bother with more testing or not.

grace
Helpful - 0
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