About mid-January I had sex (oral and genital) with my fiancee, and nothing happened. She came to visit again early March and had severe flu-like symptoms which almost made her not travel, but which subsided after a few days. We did not have sex in March but she did give me oral sex...two weeks after her return she developed a painful genital ulcer, which was diagnosed as genital herpes type-1. Naturally I thought it somehow came from me, she is beyond devastated and does not want to be with anymore, however I went to get blood tests myself soon afterwards and I tested negative for both HSV-1 and HSV-2 [Igg 0.33 and 0.25, respectively], again this is exactly 3 months after the time we had sex.
She says she has never been with anyone else but me in all her life, the last time she had sex was when she was 15. (she's 28 now). How could have this happened?
1. Could I have an anitbody-undetectable HSV1 infection?
2. If so, Is it normal for the initial outbreak to take this long to manifest?
3. Could she have been infected all her life and that what she had was a freak recurrence?
4. The probability of her cheating on me is very low.
Next, if it was a single lesion, then this is more indicative of a recurrent outbreak rather than a first infection. Most people have very infrequent outbreaks with HSV1. Hence it is possible she was infected a long time ago and is suffering an outbreak.
How long was it from the last time you have her oral sex until the ulcer appeared? If it was greater than 14 days then it is unlikely she was infected by the previous oral sex encounters (you to her).
So now to your questions:
1. Yes around 1 in 10 infections are missed by commercial HSV1 tests. Thus there is this small chance you do have HSV1.
2. You are right that any longer than 14 days is an indication that the outbreak is recurrent rather than an initial outbreak (which are usually multi-lesion)
3. Yes this is very possible.
4. For the same reasons that this doesn't seem a primary infection, the probability of cheating would be low.
I'm still on the original diagnosis though, this may hold the key!