Causes

Who Gets M.E.?

M.E./CFS exists worldwide and affects men, woman and children of all ethnic origins. Over the years, clusters of the illness have been reported in certain communities; however, no specific virus has been discovered that explains this phenomenon. Genetics are also being examined to discover possible predisposing factors that would make an individiual susceptible to M.E./CFS.

It was previously thought that M.E./CFS affected mainly the white population. This myth was dispelled in 1993 by a study of random community-based citizens in Chicago. The findings appear in the Journal of Arch Intern Med, Vol. 159, Oct.11, 1999.

This study concluded that M.E./CFS affects 522 women and 291 men per 100,000 population. Per capita, M.E./CFS affects more American women than breast cancer (26 per 100,000), lung cancer (33 per 100,000), or AIDS (12 per 100,000), and almost as many as diabetes (900 per 100,000). Other US studies have indicated that approximately 75 to 276 per 100,000 have M.E./CFS.

A Community-Based Study of Chronic Fatigue Syndrome

Background: Most previous estimates of the prevalence of CFS have derived largely from treated populations, and have been biased by differential access to health care by sex, ethnic identification, and socioeconomic status.

Objectives: To assess the point prevalence of CFS in an ethnically diverse random sample.

Design and Participants: A sample of 28,673 adults in Chicago was screened by telephone. Those with CFS-like symptoms were medically evaluated.

Main Outcome Measures and Analyses: Self-report questionnaires, psychiatric evaluations and complete medical examinations with laboratory testing were used to diagnose patients with CFS. Univariate and multivariate statistical techniques were used to delineate the overall rate of CFS in this population, and its relative prevalence was subcategorized by sex, ethnic identification, age, and socioeconomic status.

Results: There was a 65.1% completion rate for the telephone interviews during the first phase of the study. Findings indicated that CFS occurs in about 0.42% (95% confidence interval, 0.29%-0.56%) of this random, community-based sample. The highest levels of CFS were consistently found among women, minority groups, and persons with lower levels of education and occupational status.

Conclusions: Chronic fatigue syndrome is a common chronic health condition, especially for women, that occurs across ethnic groups. Earlier findings suggesting that CFS is a syndrome primarily affecting white, middle-class patients were not supported by our findings.

Leonard A. Jason, PhD; Judith A. Richman, PhD; Alfred W. Rademaker, PhD; Karen M. Jordan, PhD; Andrius V. Plioplys, MD; Renee R. Taylor, PhD; William McCready, PhD; Cheng-Fang Huang, MS; Sigita Plioplys, MD.

Studies on Multiple Outbreaks of M.E./CFS

Dr. Byron Hyde's book The Clinical and Scientific Basis of Myalgic Encephalomyelitis and Chronic Fatigue Syndrome lists instances of multiple outbreaks over the decades.

In 1984, reports of M.E./CFS began increasing in the United States and Canada. At Incline Village, Lake Tahoe, Nevada, a significant proportion of the community became afflicted with M.E./CFS. A similar phenomenon occurred in Chapel Hill, North Carolina. In 1985, there was an outbreak of M.E./CFS among children and adults in Lyndonville, New York.

Dr. David Bell has written a book called The Disease With a Thousand Names. No singular causative agent has yet been identified in the acquisition of M.E./CFS. Unfortunately, new cases continue to appear.

What Causes It?

Research, as yet, has not revealed the cause(s) of M.E./CFS, nor is there an established accepted universal treatment or diagnostic test.

The clinical history supports the hypothesis of an infectious process. There is no clear evidence for only one particular pathogen or virus at this time. However, the viral theory is confirmed by the dysregulation of the 2-5A synthatase/Rnase L antiviral defence pathway.

Future research may establish subgroup differences among M.E./CFS patients which may help explain the inconsistencies between M.E./CFS patients. Because of the waxing and waning of M.E./CFS symptoms in individuals, more long-term studies are needed to provide an illuminating picture of the illness. Genetic factors are also being explored to discover if an individual may be susceptible to M.E./CFS.

Research studies to establish diagnostic markers for M.E./CFS are also being conducted.

As yet, the number of M.E./CFS patients in research studies have been small. However, we are optimistic that this will change in the near future. Presently, most treatment is aimed at reducing symptoms and involves mainstream and complementary medicine and lifestyle management with a multi-disciplinary approach to the illness.

As you review M.E./CFS research, the number of conflicting findings may seem confusing. However, it is most encouraging that worldwide interest in exploring the physiological complexities of M.E./CFS is growing rapidly.

Genetic Links

In this article we will try to provide you with a synopsis of the research and information that is known about possible genetic causes of M.E. -Chronic Fatigue Syndrome. The CFIDS Report web site has published an article about recent research by the CDC into genetic abnormalities in people with M.E./CFS. Although you may have already read about this research elsewhere, this article does an excellent job of explaining the findings with a minimum of scientific jargon. It also addresses the common misconception that a genetic marker is only possible if M.E./CFS is an inherited trait.