Valganciclovir (Valcyte) for Chronic Fatigue Syndrome Patients Who Have Elevated Antibody Titers Against Human Herpes Virus 6 (HHV-6)and Epstein-Barr Virus (EBV)

The purpose of this study determine whether the drug valganciclovir has a significant and real benefit on the central core of symptoms experienced by patients who have high titers to EBV and HHV-6 and are experiencing long-standing fatigue and cognitive impairment (CFS). In addition, to characterize a quantifiable biological marker in these patients that will facilitate the identification of those likely to respond to valganciclovir and will make it possible to assess response to treatment.