IgM Equivocal Test

[msmith04201976]

Doctor HHH,

I am 35 year old uncircumcised man. I had protected vaginal and unprotected oral sex with CSW on June 25th. Exactly after 42 days (6 Weeks) on August 5th; I noticed some red spots on my penis shaft and under fore skin. The red spots were little itchy and no pain and no bumps at all.

Doctor said it does not look like herpes and prescribed me Clotrimazole Anti-Fungal Cream and asked me to apply for next 2 weeks. The red spots and itching went away by next day after applying the cream. I am still applying the cream as she asked me to do it for 2 weeks.
She did order the blood test for all STDs including HIV, HSV, and chlamydia, gonorrhea, syphilis and Hepatitis from Labcorp. Everything came back negative except HSV IgM Combo Test for HSV 1 and 2 which came back equivocal at 0.97.
Doctor told me that it’s because of my recent or early infection and asked me to come back again after 6 weeks and she was very much sure that my IgG test after 6 weeks will be POSITIVE for either HSV type 1 or 2.
The results for HSV tests are:
HSV 1 IgG Test: < 0.9 (Negative)
HSV 2 IgG Test < 0.9 (Negative)
HSV IgM Test (Combo for 1 and 2): 0.97 (Equivocal)
I have no other symptoms on any part of the body like blisters, bumps, sores or anything else.
I am dying with anxiety if I have HSV infection. I already had unprotected sex with my wife 4 – 5 times after my sexual encounter with CSW. I have read enough posts from you on the STD forum that IgM 0.97 is practically negative and meaningless.
My questions are:

Is it possible to have negative IgG test after 6 weeks and equivocal IgM after 6 weeks post exposure?
What are the chances that I might have passed on the infection to my wife?
Doctor told me that IgM can be equivocal on early / recent exposure (2 to 4 weeks post exposure). But I am already 6 weeks past suspected exposure. Isn’t IgM be positive after 6 weeks assuming I have not developed enough IgG antibodies yet?
Looking forward to your reply.

[Edward W Hook, MD]

Welcome to our Forum.  While tests for IgM antibodies are helpful for diagnosis of some infections, they are of little and usually no value for the diagnosis of herpes infections.  Currently available IgM tests are more often wrong than right due to problems with cross reactivity with other antibodies, including to the Varicella zoster virus that causes chicken pox and which almost everyone has, either because they had chicken pox as a child or because they were vaccinated against chicken pox.  The HSV IgM tests can also be cross with antibodies to many other viruses as well.  Finally, because many persons who actually do have HSV continue to produce IgM antibodies long after they have acquired their infections, the IgM test is a poor test for determining if a HSV infection was recently acquired.  For all of these reasons, neither the CDC nor ANY HSV expert that I know, routinely recommends IgM testing. They are just too misleading.

So, with regard to your situation, your initial illness does not sound like HSV- it was not typical in appearance and resolved far too quickly to be consistent with a HSV infection.  Had you acquired HSV and your IgM was due to recently acquired infection, your IgG test would have been positive 6 weeks later.  There is just no meaningful evidence that you acquired HSV through your extramarital activity.  I would set those concerns aside (and thus there is no reason to think that you might have given HSV to your wife either)

I hope these comments help.EWH

[Edward W Hook, MD]

Glad to help. EWH

[msmith04201976]

Thanks, Doctor Hook.

I am feeling better now. I just wish my doctor is bit more updated on this topic...

Thanks again for your help.

[Edward W Hook, MD]

this is not a debate- you'll have to figure out who you believe.  I would however suggest that you go to the 2010 CDC STD treatment Guidelines and read what the CDC says about IgM tests. You may then wish to share it with your doctor.  Good luck. EWH

[msmith04201976]

Thanks, Doc.
I spoke to my doctor this evening and explained her about your opinion on IgM tests. She is still adamant and very confident that IgM is equivocal because of recent or early infection and I will see a positive result in next 6 weeks. As per her IgM is for recent or early infections and IgG is for late infections and my IgG test is negative as infection is only 6 weeks.

[Edward W Hook, MD]

These are redundant questions.  The eqivocal value is just a number whihc according to the manufacturer means maybe there is herpes and maybe there is not.  HOWEVER, as I told you, the test is useless. Why are we still discussing it.  

I see no reason for you to be worried about herpes. EWH

[msmith04201976]

Hi Dr.

Can you reply to my last questions? I promise no more questions after that..

[msmith04201976]

One last question - the value of 0.97 on IgM test, is it practically negative as cut off is 0.9?
If I would have acquired recent HSV (either 1 or 2), shouldn't IgM be positive by now (more than 1.10) rather than equivocal?

[msmith04201976]

Dr. Hook,

Thanks for your answers.
So is it safe to assume that I did not get HSV or do I need to go for another test in 6 weeks time to make sure.
If I had infected by HSV, I should have received initial outbreak by now in 6.5 weeks either on my genitals or mouth?