Viral onset hypothesis
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citations needed (see discussion page) (2015)
The Viral onset hypothesis is a prominent theory as more than half of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) patients report falling ill after an acute viral infection. Many different viruses have been researched as possible etiological agents.
Disease onset[edit | edit source]
Some think there is a single, novel viral agent as yet undiscovered.
Others think many different viruses can initiate and sustain the disease. Viruses linked to disease onset include herpesviruses such as Epstein-Barr virus or HHV-6, enteroviruses such as coxsackie or even influenza (the flu) or a flu-like illness. Many viruses and pathogens have been investigated, with finding being mixed and no particular pathogen found.
There are several hypotheses for how the viral trigger initiates and perpetuates the disease.
Evidence[edit | edit source]
Chronic infection[edit | edit source]
Some think that there may be a low grade, chronic infection whereby the initial virus continues to provoke an immune response, especially in key areas such as the gastrointestinal tract, muscle, and the brain, brain stem, and spinal cord.
Autoimmune disease[edit | edit source]
Some think that symptoms are caused by an inflammatory process that is triggered by an initial infection and continues even after the initial virus is no longer replicating. It is possible that ME/CFS is an autoimmune response that can be triggered by many different infections.
Viral reactivation[edit | edit source]
Still others think that an immune deficiency allows otherwise common or benign viruses to replicate.
Dysbiosis[edit | edit source]
Outbreaks[edit | edit source]
See also[edit | edit source]
References[edit | edit source]
- Carruthers, Bruce M.; Jain, Anil Kumar; De Meirleir, Kenny L.; Peterson, Daniel L.; Klimas, Nancy G.; Lerner, A. Martin; Bested, Alison C.; Flor-Henry, Pierre; Joshi, Pradip; Powles, A C Peter; Sherkey, Jeffrey A.; van de Sande, Marjorie I. (2003), "Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Clinical Working Case Definition, Diagnostic and Treatment Protocols" (PDF), Journal of Chronic Fatigue Syndrome, 11 (2): 7-115, doi:10.1300/J092v11n01_02
myalgic encephalomyelitis (ME) - A disease often marked by neurological symptoms, but fatigue is sometimes a symptom as well. Some diagnostic criteria distinguish it from chronic fatigue syndrome, while other diagnostic criteria consider it to be a synonym for chronic fatigue syndrome. A defining characteristic of ME is post-exertional malaise (PEM), or post-exertional neuroimmune exhaustion (PENE), which is a notable exacerbation of symptoms brought on by small exertions. PEM can last for days or weeks. Symptoms can include cognitive impairments, muscle pain (myalgia), trouble remaining upright (orthostatic intolerance), sleep abnormalities, and gastro-intestinal impairments, among others. An estimated 25% of those suffering from ME are housebound or bedbound. The World Health Organization (WHO) classifies ME as a neurological disease.
chronic fatigue syndrome (CFS) - A controversial term, invented by the U.S. Centers for Disease Control, that generally refers to a collection of symptoms as “fatigue”. There have been multiple attempts to come up with a set of diagnostic criteria to define this term, but few of those diagnostic criteria are currently in use. Previous attempts to define this term include the Fukuda criteria and the Oxford criteria. Some view the term as a useful diagnostic category for people with long-term fatigue of unexplained origin. Others view the term as a derogatory term borne out of animus towards patients. Some view the term as a synonym of myalgic encephalomyelitis, while others view myalgic encephalomyelitis as a distinct disease.