For years, some clinicians and researchers have been maintaining that the common yeast candida is the cause of symptoms associated with CFIDS. Chronic Fatigue and the Yeast Connection by the late Dr. William Crook describes this in detail, and it has been a common experience of many clinicians that patients with CFIDS have an unnatural overgrowth of the yeast candida. In my own experience, at least 20% of patients have some history of oral candidiasis. Dr. Carol Jessup has reported that over 80% of CFIDS patients will have evidence of candida by staining scrapings taken from the mouth.
(Source: The Doctor’s Guide to Chronic Fatigue Syndrome, by David S. Bell, M.D.)