Long Covid could actually be four different syndromes but scientists admit 'we still don't know'

‘Long Covid’ could actually be split into four different syndromes, scientists today claimed.

Thousands of survivors have reported being plagued by symptoms such as fatigue, shortness of breath, muscle pain and heart arrhythmias months after beating the disease. 

But scientists are still baffled by the lasting effects of coronavirus, likened to this generation’s polio.  

Academics at the National Institute for Health Research — headed up by Professor Chris Whitty — were asked to review the limited evidence on long Covid to help both patients and doctors understand the ‘phenomenon’. 

Their findings, released today, warned that even children can suffer and it can’t be assumed that people who are at lower risk of severe illness and death from Covid-19 are also at low risk of lasting side effects. 

Doctors cautioned some mental health problems such as anxiety and depression in ‘long-haulers’, as they are known, could be down to lockdowns, as opposed to the virus itself. 

The experts also claimed that the symptoms could be grouped into four different groups: 

• Post intensive care syndrome (PICS)
• Post viral fatigue syndrome (PVFS) 
• Permanent organ damage (POD)  
• Long term Covid syndrome (LTCS) 

Dr Elaine Maxwell, the lead author of the review from NIHR, said: ‘The overwhelming message is this is not a linear condition.

‘The lack of distinction between these syndromes may explain the challenges people are having in being believed and accessing services.’

The team at NIHR, which is primarily funded by the Department of Health and works in partnership with the NHS, did not give a detailed description of each of the syndromes in the paper. 

But Dr Maxwell said some patients suffer ‘classic’ PICS symptoms. PICS occurs when critically ill patients suffer a range of health problems after a long stint in hospital.  

It may cause symptoms such as muscle weakness due to being stationary for so long – an indirect cause of the virus itself – which can make basic tasks difficult. 

PICS patients may suffer anxiety or another mental health problems, or brain dysfunction, such as inability to remember things, which can affect whether the patient can return to work. 

Some patients experience ‘fatigue and brain fog in a way that’s consistent with PVFS’, a syndrome seen after infection after other viruses like enterovirus or rubella.  

‘Some people have clear evidence of permanent organ damage caused by the virus, particularly lung damage and heart damage,’ Dr Maxwell said.

It is not clear yet if organ damage after Covid-19, also seen in the liver and pancreas, will be permanent.   

But the team admitted a ‘significant’ number of people are in the fourth category, and do not complain of continuous problems and instead suffer a ‘rollercoaster of symptoms that move around the body’.

Dr Maxwell described the fourth group as having fluctuating symptoms that are transient, and therefore difficult to test for.

She said: ‘A significant group have a symptoms that don’t fit those categories. They describe a rollercoaster of symptoms that move around the body and do not progress towards recovery.

‘We hear that some may start with a mild infection, often described as less severe than a previous chest infection, although had no fever or no cough. Symptoms then appear in different parts of the body such as the heart, skin or gut.

‘We heard from one person who had never been in hospital, who developed a crushing headache after six weeks which was later diagnosed as encephalitis. 

‘Others developed new heart arrhythmias and fainting up to six months into their symptoms journey.’

Such a wide range of symptoms, and different presentations of illness, mean that it is hard for doctors to diagnose, which means that it is equally difficult for patients to access the appropriate care, they added.

It is unclear how many people suffer with Long Covid.

But the experts noted the UK Facebook support group they drew case studies from has 35,000 members and is likely to be an underestimation. 

They added Long Covid will bear a ‘significant burden’ on the NHS as more people develop it as the pandemic wears on this winter.

NIHR academics drew on the available evidence, interviewed people suffering Long Covid and doctors.

They held a focus group with 14 members of the Long COVID Facebook group, including those who had the disease so mild it did not cause a cough or fever, to those who were hospitalised. 

The group described multiple, unpredictable symptoms across respiratory, heart, urinary, brain, skin, gut and muscle and joint systems.  

From their work, the researchers found symptoms typically fall into four categories. 

Some patients may suffer with more than one ‘syndrome’ , or from all simultaneously, further confusing the boundaries of the illness. 

Some people who had a mild illness at the start may now be having worse ongoing symptoms than patients who needed intensive care treatment.    

‘For some people there are very real psychological and mental health problems,’ Dr Maxwell said.

Dr Maxwell said it was not clear if this was due to the virus having a ‘direct impact on the brain’, or if there were complications of pre-existing mental health issues. 

The paper said: ‘Members of the steering group also felt it is important to note that some of the mental health issues may relate to “lockdown” conditions rather than to the virus itself.’

The researchers are reluctant to give a clear definition of what ‘Long Covid’ is because they fear excluding people from accessing care. 

Various researchers have tried to amalgamate the symptoms, but this has largely been based only on those with confirmed disease. 

The challenge of working out how many people have Long Covid lies largely with the fact it is not possible to retrospectively test for Covid-19.

If this were possible, it would make sure people’s symptoms have followed Covid-19 and are not down to another illness.

And it would also pick up on all those who never experienced the classic signs of the disease but have since suffered long-term effects. 

The academics said they did not like the term ‘Long Covid’ because it is too ‘vague’.

It may mean that some patients who are struggling with ongoing after-effects are being missed if they do not fall into a set definition.

Asked how many people had the condition, Dr Maxwell said: ‘We don’t know. But what I can say is the Facebook group currently has over 35,000.’

Health officials have previously estimated that 60,000 people could be suffering with long-term after effects of Covid-19. 

Dr Maxwell said: ‘It’s reasonable to assume it’s larger than people have estimated already because there is a lot of people who have not had a Covid test and so have been excluded from assessments. 

‘It’s significant and it will be a significant burden on the NHS.’     

‘There is likely to be a rise in the number of people with Long Covid in coming months,’ she added.

The team said it cannot be assumed that people who are at lower risk of severe illness and death from Covid-19 are also at low risk of ongoing Covid.

There are a number of other aspects that are unclear because there is simply not enough evidence on it yet. 

Dr Philip Pearson, a respiratory physician at Northampton General Hospital NHS Trust and review steering group member, said: ‘Is Long Covid one thing or four things? We don’t know. 

‘What is the prevalence of each four in hospitalised and on hospitalised patients? We don’t know. 

‘What are the risk factors for each of things and are they the same for hospitalisations and deaths? We don’t know. What is the economic impact? We don’t know.

‘This thing feels like it’s easier to say what it isn’t than what it is.

‘It’s not simply recovering from pneumonia. If someone fit and healthy got pneumonia, I would expect them to recover steadily and be back to their normal within about two to three months. This isn’t that.’  

Dr Maxwell added that some people with a mild infection may have worse ongoing symptoms that those most critically ill, while those who were in intensive care have no ongoing symptoms.

‘There are people who never had any support in hospital, never had a test, have no record of ever having had Covid, except their own personal history. They may be suffering far more than somebody who’s ventilated for 21 days,’ said Dr Maxwell. 

Academics said that more work is needed to help those who are suffering as they said that many are ‘not believed’ when they seek help. 

Such a wide range of symptoms, and different presentations of illness, mean that it is hard for doctors to diagnose, which means that it is equally difficult for patients to access the appropriate care.

Understanding the differences between the syndromes and their effects is vital for helping patients recover, Dr Maxwell said. 

‘People without a clear diagnosis told us they’re often not believed by health services,’ she said.

‘Those who have been diagnosed and not always recognised in other parts of the service.

‘We were told as recently as last week, as someone who has been diagnosed by their GP as having Long Covid, who’s now in month seven (of illness), called an ambulance because a new symptom and fainting and dizziness, and was told by the ambulance crews that it was caused by a panic attack.’

The team called for anyone who believes they are suffering long-term after-effects to be logged as such in their NHS records.

Then the health service should adopt an approach of a ‘working diagnosis’ to help those in need.

Academics stressed that the understanding of the effects are still at an early stage as they called on people living with the after-effects to get involved with research.