Recurring Mono in a child

My son, who will be 7 soon, had Mono last year. He had it for about 3 months; the first month and a half he had fevers, sore throat, poor appetite, stomach pain, no energy-just laid around all the time, etc.  I was taking him to the doctor every week but they didn't figure out that it was Mono until after his glands finally swelled up and he began to have symptoms of hepatitis.  After his diagnosis, his symptoms--fevers, swollen glands, belly pain, etc lasted another 6-8 weeks or so.

Nowi It has been almost a year and his symptoms have returned. He's having fevers again, he's laying around like he doesn't feel well, his appetite is practically non-existent and his glands are swollen again.  

The soonest Dr. appointment I can get for him is Tuesday.  (His doctor has been in Guatemala)  In the meantime, I am curious to know if anyone has heard of (or experienced) Mono coming back?  It seems just like how it was when he had it, but can it relapse?

Thanks