The etiology of the Chronic Fatigue Syndrome (CFS) is unknown but it
is usually considered to be postinfectious or postviral. Many
infecting agents have been suspected as causative but none has
been proven. We investigated precipitating factors in 134 CFS
patients through the use of a questionnaire, interview,
clinical examination and serology for infecting agents; 35
healthy controls completed a similar questionnaire.
CFS started with an apparently infectious illness in 96 (72%) but
a definite infection was only found in seven of these 96 (7%).
Thirty-eight (28%) had no apparent infectious onset: 15/38
(40%) had noninfectious precipitants (trauma, allergy,
surgery). There was no apparent precipitating event in 23/38
(61%). Immunization was not a significant precipitant.
Stressful events were very common in the year preceding the
onset of CFS (114/134, 85%) but these occurred in only 2/35
(6%) of the controls (p < .0001).
The onset of CFS may be associated with preceding stressful
events and multiple other precipitants. An infectious illness is
not uniformly present at the onset and no single infectious agent
has been found; CFS is most likely multifactorial in origin.
MCM: From 1994 AACFS meeting in Ft. Lauderdale