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The CDC document below my sig block summarizes the "case definition" of
Chronic Fatigue Syndrome.  Note that it says you should look in
the March 1988 _Annals of Internal Medicine_ for the full details of the
definition.
.....................................................................
Tom Flemming                    Internet: [log in to unmask]
Health Sciences Library         Ariel: 130.113.181.186
McMaster University             Voice: (905) 525-9140  x22321
1200 Main Street West           Fax:   (905) 528-3733
Hamilton, ON   L8N 3Z5
 
 
        Visit the _Health Care Information Resources_ page
        URL    http://www-hsl.mcmaster.ca/tomflem/top.html
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---------- Forwarded message ----------
Date: Mon, 11 Sep 95 14:15:10 -0700
From: Tom Flemming <[log in to unmask]>
To: [log in to unmask]
Subject: file include
 
http://www.cdc.gov/cgi-bin/includetext.pl?/General_Information/diseases/c
fs/cfs.txt
 
> CENTERS FOR DISEASE CONTROL AND PREVENTION
> Date Last Rev'd: March 9, 1995
>
> CHRONIC FATIGUE SYNDROME
>
> The Centers for Disease Control and Prevention is actively engaged in Chronic
> Fatigue Syndrome research.  This document reflects current and reliable
> information.  At this time CDC is not equipped to handle counseling, but
> suggests that you call your nearest support group.
>
> GENERAL DESCRIPTION
> Chronic Fatigue Syndrome, or CFS, is characterized by persistent and
> debilitating fatigue and additional nonspecific symptoms such as sore throat,
> headache, tender muscles, joint pains, difficulty thinking and loss of short
> term memory. On physical examination, patients may have nonspecific findings
> such as low grade fever and redness in the throat, but frequently no
> abnormalities are found. No laboratory test or panel of tests is available to
> diagnose CFS, so the diagnosis is made solely on clinical grounds. The cause
> of CFS is unknown.
>
> In some individuals, CFS appears to develop after an acute illness like
> influenza or infectious mononucleosis, both of which usually resolve within a
> few months, or after periods of unusual stress. In other persons, however,
> CFS appears to develop gradually with no precipitating event. Symptoms are
> usually most severe early in the course of illness.  Later in the illness,
> periods of partial improvement may be followed by relapses or recovery.
> While some patients have recovered after several months of illness, others
> have remained ill for many years.  The average duration and full clinical
> picture of CFS over time is unknown.  The degree to which CFS patients are
> disabled varies widely.  Some patients continue to function at home and at
> work, although at a reduced level of activity, while others become severely
> disabled and cannot perform many of the routine activities of daily living.
>
> CFS affects females and males, and adolescents as well as adults.  Most
> reported cases, however, have occurred in young to middle aged adults with
> females diagnosed more frequently than males.  It is unclear to what extent
> these demographic characteristics reflect biases among reported cases.  CFS
> does not appear to be directly transmissible from person to person, and there
> is no justification for CFS patients to be isolated.  No deaths from CFS have
> been reported.  Epidemiologic studies of CFS have not documented clear and
> consistent risk factors.
>
> The total number of persons with CFS in the United States is unknown.  CDC
> has conducted surveillance for CFS in four cities across the United States
> since 1989.  Preliminary analysis of the first three years of data indicates
> that in these sites, two to 7 adults out of 100,000 have CFS.  These figures,
> or prevalence rates, are based upon persons who meet all of the criteria in
> the CFS research case definition, which was published in the Annals of
> Internal Medicine in 1988.  Because this case definition was deliberately
> designed to be restrictive for purposes of research, these prevalence rates
> probably represent low estimates.  They should not be used to estimate the
> overall number of CFS patients in the rest of the United States because the
> cities chosen for CFS surveillance were not selected randomly.
>
> CASE DEFINITION OF CFS
> In 1987, a panel of experts met at CDC in order to define chronic fatigue
> syndrome for research purposes.  The criteria chosen to define CFS cases were
> deliberately selected to be restrictive in order to facilitate research.  The
> goal of the case definition was to identify CFS patients who were relatively
> similar in terms of their illness.  The case definition was not designed to
> diagnose all persons with CFS or to process CFS associated disability claims.
> This research case definition, which was published in March 1988 in the
> Annals of Internal Medicine, essentially requires:
>
>  1)  the presence of new and debilitating persistent or relapsing fatigue for
>      at least 6 months, and
>
>  2)  the exclusion, by medical examination and laboratory testing, of other
>      clinical conditions (including psychiatric disorders) that may also
>      cause prolonged fatigue, and
>
>  3)  the presence of a combination of 8 or more symptom and physical sign
>      criteria during 6 or more months of illness. The symptom criteria are
>      mild fever, sore throat, painful lymph nodes, generalized muscle
>      weakness, muscle aches, prolonged fatigue following exercise,
>      generalized headaches, joint pains, various nervous system complaints,
>      sleep alterations, and development of the symptom complex over a few
>      hours to a few days. The physical examination criteria are low grade
>      fever, an inflamed pharynx without pus, and enlarged lymph nodes.
>
> DIAGNOSTIC EVALUATION
> Severe persistent fatigue and other CFS symptoms can be associated with many
> other illnesses.  These illnesses include underlying major depression and
> anxiety disorders, autoimmune diseases such as systemic lupus erythematosus,
> malignancies such as ovarian cancer, lymphoma or leukemia, infectious
> diseases such as endocarditis, hepatitis, syphilis, or AIDS, and a variety of
> other diseases such as anemia, diabetes, and diseases of the thyroid, heart,
> lungs, liver, kidneys, gastrointestinal tract, and endocrine system.
>
> The exclusion of other possible diseases as a cause of CFS symptoms is the
> most important part of the diagnostic evaluation.  Since many of these
> diseases can be treated or managed appropriately following diagnosis, and
> since some of these conditions can be progressive or even fatal if untreated,
> it is absolutely imperative that a thorough medical evaluation be done before
> a diagnosis of CFS is made.
>
> The role of laboratory and radiologic testing in the diagnostic workup of CFS
> is to exclude other possible diseases.  There are no laboratory tests
> currently available, including tests for infections, tests for activation of
> the body's natural defenses against infection, or tests for immune function,
> that can identify CFS.  In particular, tests for Epstein-Barr Virus or  EBV,
> human T-cell lymphotropic virus type-II or HTLV-II, human spumavirus, and
> immunologic abnormalities should not be used to diagnose CFS.  Such tests do
> not distinguish people with CFS from healthy people and are expensive.  Some
> physicians have reported finding brain abnormalities in CFS patients using
> radiologic tests such as magnetic resonance imaging, known as MRI scans, or
> nuclear medicine brain scans such as PET or SPECT scans.  The meaning of
> these findings is unknown.  They are not unique to CFS and are not found in
> all CFS patients.  Therefore MRI and nuclear medicine scans, which are very
> expensive, should not be routinely used to diagnose CFS.  These radiologic
> scans should only be used, when clinically warranted, to exclude the
> possibility of another brain disease.
>
> CDC cannot recommend specific physicians for referral.  Our general
> recommendation is to contact the county medical society, closest university,
> or a local CFS patient support group for a referral to an internist,
> infectious disease specialist, or other physician who is knowledgeable about
> CFS.
>
> POSSIBLE CAUSES OF CFS
> The cause of CFS is unknown.  It is also unknown whether or not CFS is a
> single illness or a group of different illnesses that share common symptoms.
> A number of theories about the underlying cause or causes of CFS have been
> proposed. Some theories have focused on possible underlying viral infections,
> while others have focused on possible underlying immunologic, hormonal,
> neurologic, and psychological dysfunction.  Some of the more prominent
> theories are discussed in more detail.
>
> Possible Viral Causes
> Epstein-Barr virus or EBV, which is the virus that causes mononucleosis, was
> widely thought to be responsible for CFS in the 1980s.  Later studies,
> however, indicated that EBV was not the cause of CFS.  Most adults have
> antibody to EBV, and a positive test for EBV, even at a high level of
> antibody, does not diagnose CFS.  In addition to EBV, several other viruses
> have been proposed as possible causes of CFS, including cytomegalovirus,
> Coxsackie B virus, adenovirus type 1, and human herpesvirus 6 or HHV-6.
> Although it is possible that viral infections play a role in causing CFS in
> some patients, none of these viruses has been consistently associated with
> CFS.  More recently, there have been reports suggesting associations between
> CFS and human retroviruses. These reports, which suggested that CFS may be
> associated with human spumavirus and viruses like human T-cell lymphotropic
> virus type-II, received a great deal of attention and generated a great deal
> of excitement.  Since then, however, three published studies have failed to
> verify an association between CFS and any known human retroviruses.  At
> present there does not appear to be an association between human retroviruses
> and CFS.  The only role for retroviral testing in the diagnosis of CFS should
> be to exclude the possibility of infection with human immunodeficiency virus
> or HIV.
>
> Possible Immunologic Causes
> Several subtle immunologic abnormalities have been described in some patients
> with CFS. Results of immunologic studies as a whole have been confusing, and
> the results of some published findings are in conflict.  Recently a panel of
> distinguished immunologists and virologists from the National Chronic Fatigue
> Syndrome Advisory Council issued an official statement regarding immunologic
> and virologic aspects of chronic fatigue syndrome. In their statement, the
> following points were made:
>
>           1)   No test is diagnostic for CFS.
>           2)   There is evidence of immune abnormalities in CFS studies,
>           which suggests a pattern of chronic immune activation.  However,
>           similar findings can be found in other chronic disorders such as
>           chronic infections, autoimmune disorders, and allergies.
>           3)   Among the most frequently identified abnormalities are the
>           following:  chronic activation of T-cells, decreased function of
>           natural killer cells, reduction of subsets of CD8 positive
>           suppressor cells, and increased levels of antibody to Epstein- Barr
>           virus early antigen.
>           4)   Other immune abnormalities have been inconsistently reported.
>           These include: failure to respond to skin tests, deficiencies of
>           immunoglobulin subclasses, and abnormal CD4 and CD8 numbers and
>           ratios.
>
> Recently researchers at the National Institutes of Health reported finding
> slightly lower percentages of naive CD4 T-cells circulating in the blood of
> CFS patients than in controls.
> The significance of these reported immunologic abnormalities is uncertain,
> but to keep these reports in perspective, the following points should be kept
> in mind.  While it is possible that immunologic abnormalities may be part of
> the process that causes CFS, these abnormalities may also represent
> nonspecific immune changes that occur as part of many chronic diseases. It is
> clear, however, that severe suppression of the immune system such as that
> seen in AIDS, does not occur in CFS. The opportunistic infections common to
> AIDS are not seen in CFS.
>
> Possible Psychological Causes
> The role of psychological factors and psychiatric diseases in causing CFS is
> highly controversial and particularly difficult to study. It is clear that
> psychiatric disease, and especially depression, is frequently found in
> individuals with persistent fatigue and among patients referred for
> evaluation for CFS.  Approximately half of the individuals referred to the
> CDC's CFS surveillance system have evidence of psychiatric illness, which was
> present before the start of their CFS symptoms.  It is also clear that CFS
> patients commonly experience depression or anxiety sometime during the course
> of their illness.
>
> These kinds of findings have led some researchers to conclude that CFS is one
> specific manifestation of underlying psychiatric illness.  Other researchers,
> however, point out that many patients who develop CFS do not have evidence of
> prior psychiatric disease, and that the depression or anxiety that develops
> after the start of CFS symptoms may be a part of the CFS disease process or
> simply a natural reaction to any chronic illness.
>
> TREATMENT
> Treatment for CFS should be initiated only after the possibility of another
> disease has been excluded as thoroughly as possible.  No medication has been
> shown to be effective for curing CFS in well conducted clinical trials.  The
> current standard of treatment is to treat the symptoms of CFS.
>
> Most experts begin by recommending a regimen of adequate rest, balanced diet,
> and physical conditioning.  Moderate exercise is generally helpful to
> minimize loss of physical conditioning, but patients should take care to
> avoid over exertion since this can lead to relapses of severe fatigue and
> other symptoms.  Non-steroidal anti-inflammatory medications can be useful
> for treating headaches, and muscle and joint pains.  Since all medications
> can have side effects, a physician should be consulted for specific
> recommendations regarding drugs.
>
> Among the numerous medications claimed to be effective for treating CFS are a
> variety of antiviral and immune system modulating drugs, vitamins, and
> holistic remedies.  While some of these treatments may be of benefit to some
> patients, other treatments are expensive, are of no proven use, and are
> potentially harmful to the patient. If you are in doubt about a specific
> therapy, one or more reputable physicians in your area should be consulted.
>
> Acyclovir and gamma globulin are two medications that have undergone rigorous
> clinical testing in CFS patients. Acyclovir, which is usually used to treat
> herpes infections, was shown to be no more effective than a placebo in
> treating CFS patients. Gamma globulin, which is composed of antibodies pooled
> from many individuals, was tested in two trials. One trial conducted in the
> U.S. showed no benefit. The other trial conducted in Australia showed minimal
> benefit, but this benefit was lost after the trial ended. Currently, two
> other medications, cortisol and ampligen are undergoing controlled trials.
>
> FOR FURTHER INFORMATION
> There are several national and local non-profit support groups for persons
> with chronic fatigue syndrome.  These groups publish periodic newsletters,
> provide lists of interested physicians, and facilitate contact between
> affected persons.  The CDC does not endorse these organizations or their
> published information but provides the names and addresses of the two largest
> national organizations for further information. These are:
>
>           1)   The National CFS Association, 919 Scott Avenue, Kansas City,
>           KS.  66105.  Tel. (913) 321-2278.
>
>           2)   The CFIDS Association, Community Health Services, P.O. Box
>           220398, Charlotte, NC.  28222-0398.  Tel. (704) 362-2343
> --------------------------------------------------------------------
>
> Generated by: /usr/local/httpd/cgi-bin/includetext.pl
> Date: 18:17:6 UT on Wed 11 Oct 95.
 
 
--
....................................................................
Tom Flemming                    Internet: [log in to unmask]
Health Sciences Library         Ariel: 130.113.181.186
McMaster University             Voice: (905) 525-9140  x22321
1200 Main Street West           Fax:   (905) 528-3733
Hamilton, ON   L8N 3Z5
......................................................................