mononucleosis
"This drug literally saved my life.  
I had a "low replication" chronic epstein barr virus infection for years without knowing it.  This led to a very debilitating case of CFS for me. After 2 years I got to the point where I was so weak that I would go to sleep feeling like I might not ever wake up again. Then, I found a naturopath who put me on Acyclovir.  The first two weeks were tough because it caused a severe herx reaction, but I have been on it for 8 months now, and I feel like a living energetic person again.  This little pill literally saved me when countless doctors couldn't.  If you would like to read about treatment for CFS with this drug:  google valacyclovir and chronic fatigue"