Long Covid now has a formal definition – setting out agreed symptoms and timeframes to help spot the common post-Covid condition.
The World Health Organization’s case definition aims to help doctors across the world to assess and diagnose long Covid. The illness affects more than 1 in 3 people who have had Covid-19 disease, according to a recent study.
See below for the WHO’s long Covid definition.
The SMC asked experts to respond.
Dr Anna Brooks, Cellular Immunologist and Senior Research Fellow, Maurice Wilkins Centre, University of Auckland, comments:
“It is encouraging to see that a case definition for Long COVID – or “Post COVID-19 condition” – has been released by the WHO. This was developed as a collaborative effort by key stakeholders, including both patients themselves as well as patients who are researchers, highlighting the importance of including those with a lived-experience of having had COVID-19 and the associated persisting condition.
“We hope that by having a clinical case definition, that more patients will be listened to, and taken seriously when they seek the medical care they so desperately need. It is incredibly distressing to hear that many of those that meet this criteria here in Aotearoa have given up seeking medical care due to the trauma of being ‘gas-lit’, or dismissed by their doctors.
“This, in part, may also be due to the similarities that Long COVID has with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), another poorly-understood and often dismissed condition that can occur following viral infection. ME/CFS and Long COVID affects millions of people worldwide, yet there are no diagnostic tests or effective treatments, and clinical guidance remains inconsistent or obsolete. We hope that the international attention on Long COVID, including the announcement of a clinical case definition, will result in all post-viral conditions being taken seriously so that medical care and treatments can be developed once research is undertaken to address this global health burden.
“Vaccination will undoubtedly lower the burden of Long COVID. However, just as vaccines aren’t 100% protective, we know that Long COVID can also occur following a breakthrough (symptomatic) infection. Fortunately, these cases remain low. The study showed that in the minority of people who got Covid-19 despite being vaccinated, the odds of developing symptoms lasting longer than four weeks were cut by 50%. This is compared with people who were not vaccinated.
“So the message is clear, the odds of getting Long COVID following two vaccine doses is very low. Given Long COVID does not discriminate and can affect all ages, it is even more critical that we protect those who are most vulnerable – those who cannot be vaccinated and children who are not eligible – by ensuring we reach high vaccination rates.”
No conflict of interest declared.
Dr Stephen Ritchie, Infectious Diseases Specialist and Senior Lecturer – Clinical, Molecular Medicine and Pathology, University of Auckland, comments:
“One of the common pieces of misinformation about COVID-19 is that it is “just a bad cold” and “nothing to worry about”. While for many adults COVID-19 is likely to only cause a self-limiting influenza-like illness, the high number of deaths caused by COVID-19 around the world clearly demonstrates that COVID-19 is much more than a bad cold. Furthermore, recent research demonstrates that a high proportion of people with COVID-19 will suffer post COVID-19 (a.k.a. long-COVID) symptoms.
“Post-COVID can be devastating and is characterised by a number of severe symptoms: fatigue, “brain-fogging”, abdominal symptoms, depression, chest pain and breathing difficulties, to name a few. A recent study from Oxford University, UK, found that more than 1 in 3 people had these symptoms between 3 and 6 months after they’d recovered from their initial COVID-19 illness! Many New Zealanders already suffer from this problem and many, many more will in the future.
“There is a huge list of things that require further study for post COVID-19. High on that list is the need to find out why this happens for so many people, but not others; how to prevent it happening; and how to best help those who have post COVID-19.
“The WHO has recently increased recognition of long-COVID through a series of webinars, and today’s presentation presented information that helps to define cases of post COVID-19 (see definition below), to improve the consistency of future research internationally and to improve advocacy for people with post COVID-19.
“At present, the best way to avoid post COVID-19 is to get fully vaccinated – another UK study showed that vaccination reduced the risk of having ongoing symptoms after one month by a half.”
No conflict of interest declared.
Emeritus Professor Warren Tate, biochemist, molecular biologist and ME/CFS expert, Brain Health Research Centre, University of Otago:
“The World Health Organization (WHO) has announced a definitive clinical case definition for what has been known as Long COVID, a condition arising as an ongoing disease from the virus of the current pandemic. It is officially now named ‘post COVID-19 condition’, although I suspect the ‘street name’ will persist.
“This is a positive step in that now all research and clinical intervention will be working with a common clinical case definition for study recruitment and therapies. This has not been the case for the sister disease – Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) – where over 20 clinical case definitions exist, which means it is difficult to compare international studies if they have used different criteria to recruit patients.
“The case definition was determined after an iterative process involving contributions from patients, patient researchers, external experts and WHO staff, with a reasonable gender balance, albeit slightly skewed towards males. This is important since post COVID-19 condition occurs more in women of middle age.
“The diagnosis applies to individuals with a history of probable or confirmed Covid infection, usually 3 months from the onset of COVID-19, with symptoms that last for at least 2 months and cannot be explained by an alternative diagnosis. Common symptoms include fatigue, shortness of breath, and cognitive dysfunction. Symptoms may be new onset following initial recovery from an acute COVID-19 episode or persist from the initial illness. Symptoms may also fluctuate or relapse over time.
“There are some slightly puzzling aspects to this announcement. Long COVID has generally been accepted to be a group of post-COVID conditions (e.g. specific organ effects, post-traumatic stress disorder, and perhaps the most common, post-viral fatigue syndrome), although not with universal agreement. Here, the definition has been derived for the group and so the patients may still be diverse, requiring differing strategies for improving their health. The definition itself may eliminate some of the subgroups while including others. In reality, the symptoms chosen for the definition will largely identify the subgroup with post-viral fatigue.
“In fact, as defined here the condition’s features are incredibly similar to its sister disease ME/CFS and the WHO definition almost mimics a clinical case definition for that disease. In that sense it is surprising that people who have been suspected but not formally diagnosed with COVID-19 would be included within the definition. These could be people with ‘classic ME/CFS’ that has arisen from an alternative source.
“Although the purpose is admirable – to derive a common case definition that could be used worldwide and focuses wholly on COVID-19, it is surprising there was no clear reference in the WHO’s release to how similar this is to the clinical case definition for ME/CFS, and how these diseases should now be considered together.
“This seems to me a lost opportunity that would benefit not only those suffering from post-COVID 19 condition – but also those suffering with ME/CFS – who for many years have been out of the spotlight and largely ignored, despite their estimated numbers worldwide being equivalent currently to those predicted to have post-COVID 19 syndrome – about 20 million people worldwide. ME/CFS is very briefly mentioned under the little-used name ‘Systemic Exercise Intolerance Syndrome’, which has little public or even patient use.”
No conflict of interest declared.
The WHO definition of long Covid is: “Post COVID-19 condition occurs in individuals with a history of probable or confirmed SARS-CoV-2 infection, usually 3 months from the onset of COVID-19 with symptoms that last for at least 2 months and cannot be explained by an alternative diagnosis. Common symptoms include fatigue, shortness of breath, cognitive dysfunction but also others which generally have an impact on everyday functioning. Symptoms may be new onset, following initial recovery from an acute COVID-19 episode, or persist from the initial illness. Symptoms may also fluctuate or relapse over time. A separate definition may be applicable for children.”