Disregard the IgM. It's inconclusive for a number of reasons, some of which you've already mentioned, plus this important one: it can detect other viruses besides HSV, including chickenpox and mono, and usually fails to distinguish among them. It is useless. Verify here, on this highly-credentialed site (ASHA):
A positive on a culture swab is virtually never wrong, unless the sample was contaminated. However PCR is a DNA test, not culture. In that case as well, however, a positive result is pretty definitive, except in cases of lab contamination. Whether one already has a prior infection is of no consequence, if the test is type-specific.
The HSV types (1&2) do not "cross the equator" from above to below the waist and vice versa. However, they can each infect either site - they are not limited to their site of preference.
According to your evidence, you are both experiencing a first infection of HSV-2, which does not seem possible, unless you've each had other partners in the last 4 months. However, if your IgG tests were the HerpeSelect IgG ELISA, they could have returned inaccurate results for either or both of you. The ELISA sometimes (a) misses HSV-1, (b) mistakes HSV-2 for HSV-1, and (c) returns false positives when the ab count is under 3.5 or so.
What I recommend: get the pricey but conclusive Western Blot - the gold standard of tests. You can wait until the 16-week mark to do this, and it will be conclusive. You can also re-test between now and then with the IgG, say at the 8-week mark, to see if the antibody count has changed, just to give yourself an idea of the virus' progression.
Dr. Anna Wald of the University of Washington told me that about 75% of the population has one or both types of HSV, about 65% has HSV-1, and about 16.9% has HSV-2. This would lead one to calculate that about 7% of us have both - that's over 22 million people.
Hope some of this helps.
Hi, first we dont use igM for testing as is not accurate only igG type specific. Also a non primary first genital outbreak means you tested positive in the genital area but never had an outbreak before? This doesnt make much sence. A non primary means your were diagnosed positve before and if it was genital testing means you had a swab done. Please clarify.
Also if med express tested igG negative for hsv2 and planned parenthood tested positive with the culture means this is a new infection. Swabs are extremely accurate only showing a negative for a swab would be questioned not a positive.
Having both hsv1 and 2 is possible but not common.
To try to help clarify about why I requested an IgM with the IgG:
The IgM is notorious mostly because it has a high false positive rate and does not determine type. It's area of use comes when it is taken together with an IgG. It can give some additional insight into whether an outbreak is a first or primary outbreak for some individuals. (however 30-70% of individuals will test positive with a recurrent HSV infection) I had added it to the other tests just as a potential peace of mind while waiting for the culture which usually takes several days to over a week longer.
My concern with the IgM is that it is potentially a false NEGATIVE. As in this is the first time that I've had a genital outbreak (first infection) but it is non-primary (I already have HSV1 orally), it has a small window that it could test negative in: ie being a HSV1 genital outbreak that does not make the IgM positive. Which happened, the IgM was negative----despite one of the cultures coming back positive! Confusing, yes I know. I understand now that this may be due to a low statistical power of the test---which is still surprising as it was three days into an active infection.
Clarifying further on the non-primary first:
I have had oral HSV1 since childhood, meaning HSV1 is the primary HSV infection. However I have never had a genital outbreak so this outbreak is my first outbreak.
I do realize that this is a new infection.
My questions were more specific:
How accurate are swab tests when patient already has 1 strain of HSV? (percentages?)
I understand it is rare to have both types of HSV, but what are the actual percentage rates in the population?
One thing I failed to mention that might be important:
The blood tests look for antibodies to the virus, which can take up to 16 weeks to generate in the system enough to trigger a positive result. Therefore, a positive swab and a negative IgG is a sure indication that it's a new infection.