Hi,
I have no experience with CMV, but, when I was young ( long time ago) I was positive for EBV and HHV6 and now, with a blood test we didn't see anything.... We had to do a biopsy ( stomach) to see that EBV and HHV6 are still there...
The blood test shows no antibodies... But the biopsy well. It seems that it was because the viruses were asleep. Cross my fingers...
Have a nice day
Clodomir