[Question #4387] Positive HSV IGM Test Result

30 months ago
Good evening doctors,
I received unprotected oral sex from a person of unknown HSV status. She did not have any visible outbreaks at the time. I had a full STD panel done 8 days after this event. All tests were negative with the exception of the HSV IGM I/II ABS which came back positive at 1.6. The type specific HSV IGG tests both came back negative in this panel. I had another STD panel done at a different lab 23 days after the event. All tests including the type specific HSV IGG tests came back negative. This panel did not include the HSV IGM test. It is now 36 days since the incident and since that time, I have not experienced any of the symptoms of herpes that are described on various medical websites and forums, no sores , no pain, redness, blisters or burning sensations, and I have been checking obsessively. Does the positive HSV IGM test indicate that I have contracted HSV? Should I get tested again and are there any other tests I can request? 

Thank you
Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
30 months ago
NO!  The CDC says never to use the IgM test to try to diagnose herpes in the adult and in my experience, it is falsely positive (that is, the IgG test does not go on to be positive in the future).  It should never have been ordered for this very reason (false positives).  If you have had no symptoms since this encounter and have been looking carefully for any symptoms, I think it is unlikely that you have contracted HSV from this encounter.   Have you ever in your whole life had a cold sore on  your lip or in your nose?

Terri
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30 months ago
Good evening Terri,
Thank you for your response. No, I have not had a cold sore before on my lip or nose. I have not noticed any difference or new sensations on my lips, nose or genitalia after this encounter. What is the typical window to develop herpes symptoms if I have indeed contracted it from this encounter? Is the negative IGG type specific tests after 23 days conclusive or do I get this test again? Can symptoms develop this long after the exposure, 36 days? There is a lot of confusing information on the web. 

Thank you 
Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
30 months ago
The typical window is 2-10 days from the encounter to development of symptoms.  A test at 23 days is not conclusive - a test at 6 weeks picks up about 70% of those who are going to be picked up by the test but the IgG test for HSV 1 misses 30% of infections compared to the gold standard western blot.  Not everyone who gets herpes develops symptoms right away - some don't show symptoms for years (or miss their symptoms when they do appear or confuse them with something else)

Terri
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29 months ago
Hello, I had follow up IGG type specific tests at 64 days which came back negative. I am relieved but the day after the test results, day 68, I noticed a tiny lesion type bump just below the glans on my penis. It didn’t/does not hurt when I touched it, nor did I have any other symptoms of note.  This was the only abnormality I noticed. I have not had any sexual contact since the the original exposure. Could this be herpes? Could IGG test results be negative and still show physical signs of herpes this long after possible exposure?
Thank you
Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
29 months ago
The IgG test does not pick up all infections - when you get a symptom like this you should see a provider and get a swab test done, just to be certain.
The IgG test misses 30% of HSV 1 and 8% of HSV 2 infections compared to the gold standard western blot antibody test for herpes.

Terri
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