It means it will never go away, and can pop up at any given time. Usually because you are stressed. If you had been diagnosed earlier they could have given you anti-virals, which may have helped, but because you weren't, your pretty much at the diseases mercy.
I say this only from my own experience.
I was mis-diagnosed with Fibromyalgia, even after the rheumatologist knew I had tested positive for EBV in the past.