Celica
There is no treatment per se for EBV infection, often the cause of infectious mononucleosis, other than treating the symptoms[fever control, proper nutrition, rest, etc]. The course of the clincal picture usually runs around 3-4 months. CFS - being very ambiguous, is another tricky creature, since there are several etiologies - infectious, immunologic, psychiatric, among others. Tricyclic antidepressants and SSRI's tend to be the common route of treatment for CFS patients.
Hope I helped.