Once you have contracted EBV, it stays in your body for life, although it's usually dormant after the initial phase. It's most likely to be spread during the acute phase, but it can actually be spread at any time after you've contracted it. I don't know for sure about CMV (I think that's what you were trying to ask about), but I assume it would proabably be similar. Please keep in mind I'm not a doctor, so I can't say 100% that these answers are correct, but I think they are!
I'm noticing we're not getting alot of replies in this forum.