Aetiology and pathogenesis

• the aetiology and pathogenesis are poorly understood (1,2,3)

Prior to diagnosis, CFS patients are usually healthy with a good quality of life.

Approximately 50-80% of people with ME/CFS start suddenly with a flu-like illness.

ME/CFS is often found after infection by a virus, bacterium, or parasite, suggesting an immunological dysfunction, along with a genetic predisposition.

Viral involvement is a well-supported theory due to the high index of an infectious onset in at least half of the patients.

• it is unclear whether infections have a role in the continuing illness or act as a trigger in predisposed individuals
• other noted triggers include chemotherapy and immunisations
• CFS patients may show features of other syndromes, particularly fibromyalgia and irritable bowel syndrome. This association suggests that these syndromes may share similar pathogenetic, predisposing or trigger factors

References:

1. Cortes Rivera M et al. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Comprehensive Review. Diagnostics (Basel). 2019 Aug 7;9(3)
2. Myalgic encephalomyelitis (or encephalopathy)/chronic fatigue syndrome: diagnosis and management. NICE guideline NG206. (October 2021)
3. Bested AC, Marshall LM. Review of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: an evidence-based approach to diagnosis and management by clinicians. Rev Environ Health. 2015;30(4):223-49