Letter to the Editor
We are writing to highlight the potential for a post-viral syndrome to
manifest following COVID-19 infection as previously reported following
Severe Acute Respiratory Syndrome (SARS) infection, also a
coronavirus.1 After the acute SARS episode some
patients, many of whom were healthcare workers went on to develop a
Chronic Fatigue Syndrome / Myalgic Encephalomyelitis (CFS/ME) - like
illness which nearly 20 months on prevented them returning to
work.2 We propose that once an acute COVID-19
infection has been overcome, a subgroup of remitted patients are likely
to experience long-term adverse effects resembling CFS/ME symptomatology
such as persistent fatigue, diffuse myalgia, depressive symptoms, and
non-restorative sleep.
Post-mortem SARS research indicated the virus had crossed the blood
brain barrier into the hypothalamus via the olfactory
pathway.2 The pathway of the virus seemed to follow
that previously suggested in CFS/ME patients, involving disturbance of
lymphatic drainage from the microglia in the brain.3One of the main pathways of the lymphatic drainage of the brain is via
the perivascular spaces along the olfactory nerves through the
cribriform plate into the nasal mucosa.4 If the
pathogenesis of coronavirus affects a similar pathway, it could explain
the anosmia observed in a proportion of COVID-19 patients.
This disturbance leads to a build-up of pro-inflammatory agents,
especially post-infectious cytokines such as interferon gamma, and
interleukin 7,5 which may affect the neurological
control of the ‘Glymphatic System’ as observed in
CFS/ME.3 The build up of cytokines in the Central
Nervous System (CNS) may lead to post viral symptoms due to
pro-inflammatory cytokines passing through the blood brain barrier in
circumventricular organs such as the hypothalamus, leading to autonomic
dysfunction manifesting acutely as a high fever and in the longer term
to dysregulation of the sleep/wake cycle, cognitive dysfunction and
profound unremitting anergia, all characteristic of CFS/ME. As happened
after the SARS outbreak, a proportion of COVID-19 affected patients may
develop a severe post viral syndrome we term ‘Post COVID-19 Syndrome’ -
a long term state of chronic fatigue characterised by post-exertional
neuroimmune exhaustion.6
In a contracted future economy, managing these likely Post COVID-19
syndrome cases, in addition to existing CFS/ME cases will put additional
burden on our already hard pressed healthcare system. We suggest that
priority is given to exploration of pragmatic relatively low cost
techniques to treat post-viral fatigue, to alleviate symptoms and
improve quality of life for those affected by the longer term sequelae
of COVID-19.