Epidemic neuromyasthenia and chronic fatigue syndrome in west Otago, New Zealand. A 10-year follow-up

Abstract:

BACKGROUND: In 1984, an outbreak of an illness characterized by prolonged unexplained fatigue was reported in West Otago, New Zealand. This outbreak resembled other reported outbreaks of epidemic neuromyasthenia in that affected individuals presented with a spectrum of complaints ranging from transient diarrhea and upper respiratory disorders to chronic fatigue syndrome (CFS).

OBJECTIVE: To obtain a perspective on the natural history of CFS not possible in clinic-based studies.

METHODS: Twenty-three of the 28 patients in the original report were contacted and asked to complete written questionnaires. Interviews were obtained in person or via telephone.

RESULTS: Ten (48%) of the 21 patients with satisfactory interviews appeared to meet the current Centers for Disease Control and Prevention (CDC) case definition of CFS, and 11 were classified as having prolonged or idiopathic fatigue. A return to premorbid activity was seen in most (n = 16 patients, although some reported the need to modify their lifestyle to prevent relapses. A female predominance was noted in those meeting the CDC case definition for CFS, whereas males predominated in patients diagnosed as having prolonged or idiopathic fatigue.

CONCLUSIONS: The high proportion of patients recovering from CFS in the West Otago cluster suggests that epidemic-associated CFS has a better prognosis than sporadic cases. Female sex was confirmed as an important risk factor for CFS.

 

Source: Levine PH, Snow PG, Ranum BA, Paul C, Holmes MJ. Epidemic neuromyasthenia and chronic fatigue syndrome in west Otago, New Zealand. A 10-year follow-up. Arch Intern Med. 1997 Apr 14;157(7):750-4. http://www.ncbi.nlm.nih.gov/pubmed/9125006

 

The natural history of concurrent sick building syndrome and chronic fatigue syndrome

Abstract:

An outbreak of chronic fatigue syndrome linked with sick building syndrome was recently described as a new association. Whether chronic fatigue syndrome acquired in this setting tends to remit or, as sporadic cases often do, persist, is unknown.

To clarify the natural history of chronic fatigue syndrome in association with sick building syndrome the 23 individuals involved in the outbreak were interviewed four years after the onset. In the previous interview one year after the onset of symptoms, 15 (including 5 with chronic fatigue syndrome and 10 with idiopathic chronic fatigue) of the 23 noted fatigue. Three years later 10 of the 15 were “fatigue free” or “much improved”.

Five were only “some better”, “the same”, or “worse”. Three of the five people previously diagnosed with chronic fatigue syndrome were “much improved” (two) or “fatigue free” (one). The remaining two were seriously impaired, homebound and unable to work.

The 10 individuals with substantially improved fatigue (three of the five with chronic fatigue syndrome and seven of the 10 with idiopathic chronic fatigue) were more likely to have noted improvement in nasal and sinus symptoms, sore throats, headaches, and tender cervical lymph nodes when compared to those with a lingering significant fatigue (p < 0.001). Upper respiratory symptoms and headaches improved in those with reduced fatigue but remained problematic in those with persisting significant fatigue.

We conclude that the fatigue related to sick building syndrome, including chronic fatigue syndrome, is significantly more likely to improve than fatigue identified in sporadic cases of chronic fatigue syndrome.

 

Source: Chester AC, Levine PH. The natural history of concurrent sick building syndrome and chronic fatigue syndrome. J Psychiatr Res. 1997 Jan-Feb;31(1):51-7. http://www.ncbi.nlm.nih.gov/pubmed/9201647

 

Epidemiologic advances in chronic fatigue syndrome

Abstract:

Epidemiologic studies of chronic fatigue syndrome (CFS) have been hampered by the absence of a specific diagnostic test, but with increasing interest in this disorder there has been a greater understanding of the risk factors, illness patterns, and other aspects of this multisystem disorder.

Working case definitions have been developed for research purposes but they have continued to change over time and have not always been utilized precisely by various investigators. This has been a major factor in the widely varying estimates of prevalence rates, but two different studies using the same working definition and including a medical work-up have estimated the prevalence to be approximately 200/100,000. Clusters of CFS cases, which appear to be related to earlier reports of “epidemic neuromyasthenia”, have attracted considerable attention and appear to be well documented, although investigated with varying methodology and often with dissimilar case definitions.

Risk factors for cases occurring in clusters and sporadically appear to be similar, the most consistent ones being female gender and the co-existence of some form of stress, either physical or psychological. The prognosis of CFS is difficult to predict, although cases occurring as part of clusters appear to have a better prognosis as a group than sporadic cases, and those with an acute onset have a better prognosis than those with gradual onset.

It is highly unlikely that there is a single agent, infectious or noninfectious, that is responsible for more than a small proportion of CFS cases and, at the present time, the risk factors for developing CFS appear to lie more prominently in the host rather than the environment.

 

Source: Levine PH. Epidemiologic advances in chronic fatigue syndrome. J Psychiatr Res. 1997 Jan-Feb;31(1):7-18. http://www.ncbi.nlm.nih.gov/pubmed/9201643

 

Clinical spectrum of postviral fatigue syndrome

Abstract:

Many different neurological and psychiatric syndromes follow viral infections, but their clinical pictures and pathogeneses are poorly understood. The syndromes include acute disseminated encephalomyelitis (post-infectious encephalomyelitis), the Guillain-Barre syndrome (post-infectious neuritis) and Reye’s syndrome.

Recently, attention has been focused on another common postviral neurological syndrome, i.e. the postviral fatigue syndrome (PVFS)–termed myalgic encephalomyelitis (ME) and a host of other designations. PVFS occurs both sporadically and in epidemics, with cases being reported from all over Europe, the United States, Australasia and South Africa.

It is difficult to make the diagnosis and this has meant, in the past, that it is not until an epidemic has occurred that random cases which presented in the preceding years are realised to represent the same condition. With renewed interest in the syndrome and greater attention from physicians, however, diagnosis of sporadic cases is now becoming more common.

 

Source: Behan PO, Bakheit AM. Clinical spectrum of postviral fatigue syndrome. Br Med Bull. 1991 Oct;47(4):793-808. http://www.ncbi.nlm.nih.gov/pubmed/1794085