LAUSR

Description Myalgic encephalomyelitis and Long Covid have overlapping presentation Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe condition characterized by post-exertional neuroimmune exhaustion (PENE) accompanied by neurological, immunological, gastrointestinal (GI), and mitochondrial disturbances (1). The global prevalence of ME/CFS is ∼1%, affecting 17 million to 24 million people (2). ME/CFS is heterogeneous not only in symptom presentation but also illness trajectories, which can be worsening, plateauing, improving, or relapsing-remitting. Approximately 25% of patients with ME/CFS are considered severe and are bound to their homes. Although the etiology of ME/CFS is elusive, a large proportion of patients (∼60%) report post-infectious onset, such as after Epstein-Barr virus infection (3). The recent emergence of a chronic post-infectious condition, called Long Covid, overlaps considerably with ME/CFS in immunological, mitochondrial, and neurological dysfunctions (4). These similarities have resulted in increased interest and acceptance of ME/CFS as a disease and may stimulate research, the development of a diagnostic test, and pharmacotherapeutic interventions in ME/CFS that may be applied to Long Covid.