Question:
Hi, I was just tested negative for HSV-1 (0.51) and HSV-2 (0.86) using Herpeselect (ELISA I think). I never had any cold sores or sores on/near my genitals. I haven't been with anyone for a year. Is it possible that I have been exposed to HSV-1 when I was young, or would I probably still test positive for antibodies? I read some people say the antibody level can drop over time, but haven't seen any scientific studies that discuss that.

Answer:
Your results technically are negative. Any levels that show up below a certain amt are called negative because they could result from some non-specific (i.e. non herpes) activity.

So, probably you are negative. If you have no reason to believe you were exposed, you haven't been with a lot of partners, your partners haven't been with a lot of partners, etc, then you can have higher confidence in your results. For people who think they may have been exposed, retesting at a later date is a good idea as viral activity can fluctuate and possibly increase antibody levels, even if there is no visible outbreak.

There are people who have gotten false negative results, so it does happen. It is also possible for antibody levels to fall below the limits of detection for the tests.

I haven't seen any study that directly assesses herpes antibody levels over time. The only indication that in some people they must fall to very low levels is that all current tests available to doctors are subject to false negatives. For the tests out there, there range of false negatives is estimated at 1-10% (different figures reported everywhere... usu to get approval a better result is obtained and then someone publishes some real world results and the rate is worse).

Answer:
Thanks for the reply. I guess I'm also looking from the perspective of dating someone that says they are negative and tests negative. I would guess that I should feel pretty safe then (and they about me).

I would think if someone is shedding (say, at least once a year), then their body would produce detectable amounts of antibody, so usually would test positive. I'd like to think if they test negative then that probably means they either don't have the virus, or are not shedding anymore. But from what I can gather, even if someone stops having outbreaks they still shed which would mean they'd usually test positive.