[Question #1614] HSV Testing HSV IgM ab ela reactive HSV IgM ifa negative

53 months ago
I'm male, possibly have had exposure to HSV 2 through unprotected vaginal and oral sex in the past and vaginal to facial contact as recent as one month ago.   Had blood testing and culture of sore on my thigh done this week.  Culture was neg for hsv, some staphylococcus present.  Hsv 1 test IgG positive, HSV  2 IgG negative.  Hsv IgM ab ela reactive with confirmatory test hsv IgM ifa negative.  I've had oral cold sores since I was a kid so I know I have hsv 1.  What does the IgM ifa negative test mean?   I had cold sores one on lip, tongue and inside mouth the day after facial to vaginal exposure one month ago.  Is the reactive IgM related to the cold sores last month or infection of hsv 2?  I've not had any sores in my genital area before.  Thank you.  
Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
53 months ago
The IgM is a poor poor test but its main problem appears to be false positives.  It looks from your post like the final IGM was negative?  Anyway, ignore it, it's terrible test, either way, in my opinion.  I would trust the negative HSV 2 IgG to reflect, with 95% certainty, your antibody status 3 months ago and back.  If you have had recent contact (less than 3 months ago), this test may not reflect the input of those partners.  So, so far so good!

Terri
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53 months ago
If I had oral contact, mouth to vagina and unprotected vaginal sex about 10 days after an outbreak began with an hsv 2 woman, I have hsv 1, and had a sore on my tongue, outer lip and inside my mouth the next day and with the pos IgM result could that indicate new hsv 2 infection?   Does the ifa follow up to the IgM nullify the initial IgM?   These are the main concerns.   Thank you.   
53 months ago
So my follow up about the test is clear.  I've had mono many years ago.  I read the IgM can falsely react to mono.  How much does the IgM tell me of a possible new infection and how confident can I be with the ifa result being negative regarding new infection.  The overall testing was 25 days post the unprotected contact I described. 
53 months ago
I really appreciate this info on this site and your help.  I'm trying to make the question clear so I can get the info fir my concern.    Does the ifa result nullify the reactive ela reactive for the IgM?  I dont get why the confirmatory ifa is needed.   Is it likely the sores on my mouth the day after unprotected contact were in response to new exposure to hsv2 or my hsv 1 acting up?   The IgG test I read is 50-60% accurate after 3-4 weeks.  Thinking I should retest at 12.  Would you agree?  Hope this clarifies.  
Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
53 months ago
I get the question.  But what I'm telling you is that the IgM is terrible test and unreliable and I can't comment up on it much further because it is such a mess of test.  In my experience with the IgM, it is wrong (falsely positive) between 70-80% of the time  - that is, the person never becomes positive by IgG test, the far more reliable one.  Yes, at 3 weeks from exposure, 50% of people who are going to become positive will be positive.  Testing at 12 weeks is optimal, without any extended use of antiviral therapy, for sure. 
Since you already have HSV 1, I think it is more likely that your mouth sores are due to reactivation of HSV 1 rather than new HSV 2 orally - more likely, but I can't be sure.  I take it you did not have these swab tested?  If you get more, you could have them swab tested for more information

Terri
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