Long Covid: What the research shows

A Summary of Medical Papers on Long Covid, & Long Covid in Children

As the dialogue has shifted away from elimination (everywhere but China) and towards endemic SARS-COV2, there seems to be a trend (well, on Twitter at least) towards emphasizing the long term health effects of Covid, and primarily “Long Covid.” While there seems to be enough evidence to support the existence of specific, lingering symptoms, there does not seem to be a good consensus on it’s exact definition, or exactly how prevalent it is.

The existence of persistent post viral symptom’s is not necessarily unique to SARS-COV2. Some people who have recovered from other acute viral illnesses go on to have long-term symptoms, which has been described as “Post-viral fatigue syndrome.” This paper explains the phenomena:

“Epidemiological issues raised by the early epidemics, including the delineation of the syndrome, the question of bias, the role of hysteria and the role of depression; the issue of symptom distribution, and its implications for aetiology; and a multiaxial framework for understanding the association with psychological symptoms are discussed. The value of a future multidisciplinary research programme designed to disentangle direct and predisposing causes of PVFS is emphasised.”

Sometimes it’s important to look back to the past, before making presumptions about the future or immediately concluding that the thing we are trying to study is “new.”

So, at the risk of being accused of either minimizing or exaggerating the risk and seriousness of Long Covid, allow me to frame the following information with quote from microbiologist Gerald Domingue from a paper in ‘Frontiers in Pediatrics’

“It is unwise to dismiss the pathogenic capacities of any microbe in a patient with a mysterious disease” (1). This thinking greatly applies to the illness [Myalgic Encephalomyelitis/Chronic Fatigue Syndrome]. ME/CFS is characterized by neuroinflammation, severe fatigue, excessive post-exertional exhaustion, disturbed sleep, flu-like episodes, cognitive problems, sensory hypersensitivity, muscle and joint pain, headache, bowel symptoms, and severe impairment of daily functioning (2).

While many are emphasizing Long Covid as a justification for continued restrictions and non-pharmaceutical interventions, others have pointed out quite brilliantly that we’re all getting Covid, eventually. Recent articles have made claims that it’s really Long Covid behind the labor shortages. They go so far as to call it a “Public Health Crisis,” though somehow that crisis is also “invisible.” I can’t help but think- If long Covid is so prevalent, and if everyone is getting Covid, how exactly could this be an “invisible” public health crisis?

Acknowledging the real individuals who struggle with these continuing symptoms, we should try to investigate whether or not the Long Covid phenomena is new, unique, or more prevalent than post viral syndromes from other endemic respiratory diseases.

The questions that need to be asked about long Covid:

How frequent is it?

Is it correlated to the initial severity of disease? And therefore stratified by age?

Is it more frequent than post-viral syndrome is after other endemic respiratory diseases, like the flu?

Have the specific symptoms of Long Covid caused a population-level increase in incidence of said symptoms?

I believe that the following papers answer some, but not all of the previous questions. We need to look at well designed studies that include control groups, and do not make the mistake of extrapolating small sample size effects to the population at large, which many “Long Covid” papers do. What’s important to consider when researching this subject is the methods and the sample that the researchers employed. Did they start with only a group of people who were classified as having Long Covid, and focus the majority of the study on findings from that group? This is a common problem I observe in medical or science writing for the general public.

So, in an effort to provide a referenceable summary of the literature, I have summarized what I consider to be the key points and key findings of the papers. I hope this can serve as a useful repository for accurate, trustworthy research on this subject. I’ve included 12 papers I consider to be significant in their contribution to the topic: 7 on the subject of Long Covid in Adults, and 5 on Long Covid in kids.

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Long Covid is poorly defined:

Clinical coding of long COVID in English primary care: a federated analysis of 58 million patient records in situ using OpenSAFELY

“Current recording of long COVID in primary care is very low, and variable between practices. This may reflect patients not presenting; clinicians and patients holding different diagnostic thresholds; or challenges with the design and communication of diagnostic codes. Increased awareness of diagnostic codes is recommended to facilitate research and planning of services, and also surveys with qualitative work to better evaluate clinicians’ understanding of the diagnosis.”

One paper even explains

“Given that there is no universally agreed definition of Long COVID, we elected not to start with an arbitrary definition of a new condition but to seek the descriptions from almost 7,000 Children and Young People of their physical and mental experiences in the months following a SARS-CoV-2 test”

Another paper in Nature actually confirms that the term “Long Covid” did not even originate from the medical community, but that the term was

“First coined by people sharing their experience of ongoing symptoms on social media and establishing support groups.”

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Long Covid in Adults: