http://www.anapsid.org/cnd/diffdx/klapow.html

This is a link to a study regarding the prevalence of Cryptostrongylus Pulmoni a roundworm parasite and its link to people suffering from CFS. It is basically a hidden lungworm which hides in the lungs and causes all kinds of symptoms.

Cryptostrongylus pulmoni infects a large percentage of CFS patients, estimated at 66 percent in the current study, and is significantly associated with the syndrome.

Also many people with simply fatigue issues have some kind of parasitic infection and can relieve their fatigue with a parasite cleanse and evaluating their diet.

I myself thought i had CFS, lyme disease, even was diagnosed as having peripheral neuropathy turns out due to my own good judgement and trial of anti-parasitic medications / herbal remedies most of the symptoms reduced themselves to a good degree. I actually have an chronic hidden infection of strongyloidiasis which are worms and have lodged themselves inside my muscles and spinal cord causing neurological symptoms, fatigue etc...

Ivermectin is a anti-parasitic medication some CFS patients have been using with success which has started to relieve their symptoms. It is effective against C.Pulmoni might be worth a try