Long COVID 'May Be Four Syndromes'

The condition commonly called 'long COVID' may not be one syndrome but possibly up to four different syndromes, according to a new review.

The finding comes from a dynamic themed review of available scientific evidence published by the National Institute for Health Research (NIHR).

The paper, Living with COVID19 draws on the latest expert consensus and published evidence, as well as the experience of patients.

It formed the first output from the NIHR Centre for Engagement and Dissemination (NIHR CED) which is working towards a real-time knowledge base in what is an emerging field.

It is estimated that as many as 60,000 people in the UK may have long COVID.

Long COVID 'May Be a Catch All Term'

The review found clear consistencies for a wide range of recurring symptoms among people who had been hospitalised because of COVID-19, as well as those who had COVID-19 in the community.

Those who experienced ongoing COVID had problems with the respiratory system, the brain, cardiovascular system and heart, kidneys, the gut, the liver, and even skin.

The authors said that such a wide range of symptoms created diagnostic uncertainty.

"We believe that the term 'long COVID' is being used as a catch-all for more than one syndrome, possibly up to four," said Dr Elaine Maxwell, the review's author.

She told a briefing hosted by the Science Media Centre (SMC) that while some patients experience "classic post-critical illness symptoms", others reported "fatigue and brain fog in a way that's consistent with post viral fatigue syndrome".

A third group experienced "permanent organ damage caused by the virus", while another significant group "describe a rollercoaster of symptoms that move around the body and do not steadily progress towards recovery".

"We believe that the lack of distinction between these syndromes may explain the challenges people are having in being believed, and accessing services," said Dr Maxwell.

Patients who were unable to have their symptoms addressed and treated in the absence of an agreed definition of ongoing COVID, particularly those who were not hospitalised and never formerly diagnosed, may in turn go on to encounter a psychological impact, the review said.

Ongoing COVID 'Can Last for Months'

Another notable feature of ongoing COVID was a wide spectrum in how long patients reported feeling unwell.

"People asking for help and advice now are being told that they should recover within 2 to 3 weeks," said Dr Maxwell, "but we heard from people who are still unable to work, study, or care for dependents 7 months after their initial infection."

As part of the study, the NIHR CED held a focus group with 14 members of the Long COVID Facebook group, whose members include post-hospitalised and non-hospitalised people.