There’s something else going on here.
What if a large chunk of the population with symptoms fitting the definition of a post-infective syndrome never had the infection in the first place?
You’d be taking another look at that definition, the Back Page assumes, and that’s the position the World Health Organization may now be in with regards to long covid, or what it calls post-covid-19 condition (PCC).
An international team led out of Norway, with researchers from Australian centres including the Kirby Institute, have published a study in JAMA Network Open that may confirm your doubts about the stretchy and non-specific nature of the WHO definition of PCC:
“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, and cognitive dysfunction … and generally have an impact on everyday functioning. Symptoms might be new onset after initial recovery from an acute covid-19 episode or persist from the initial illness. Symptoms might also fluctuate or relapse over time.” (See here for the questionnaire used to determine the “minimum and essential domains” for the definition.)
The team took a sample of young people (aged 12-25) testing for SARS-CoV-2 and gave them “a clinical interview and complete physical examination, recording of vital signs, functional testing, blood sampling” and a questionnaire to complete, soon after their test (early convalescent period for those who had covid) and again six months later. The final analysis included 382 who had tested positive and 85 negative.
Subjects were assessed based on their clinical and questionnaire results for PCC with the assessors blinded to covid test results.
There was no association between SARS-CoV-2 infection and post-covid-19 condition.
That’s right: there was no significant difference in PCC rates between the positive and control groups, with just under half of each group qualifying for the diagnosis (48.5% and 47.1% respectively).
There was a similar slightly and non-significantly higher prevalence of post-infective fatigue syndrome (PIFS) in the covid-positive group.
The main risk factor for persistent symptoms at six months was severity of symptoms at baseline (regardless of covid result).
Other notable risk factors at baseline for both PCC and PIFS, the authors write, were “female sex, low self-reported level of physical activity before infection, loneliness, and negative life events during the preceding year”.
The non-covid phenomena that would explain their results, the authors say, are 1) that fatigue, shortness of breath and memory problems are common in the general population; and 2) that the pandemic created mental distress in the general population which could be affecting physical symptoms.
The obvious implication is that persistent symptoms in some people who have had covid may also not be due to covid.
As the authors write: “nonspecific stressors either unique to or increasing during the pandemic, and which affected both SARS-CoV-2-positive and SARS-CoV-2-negative individuals similarly, may be important for symptom persistence and associated disability. This possibility should be considered when societal countermeasures against infection outbreaks such as lockdowns are implemented.”
They cite a study undertaken in 2020-21 that found believing one had experienced covid was more associated with persistent symptoms than actual positive serology.
Another, older study found that PIFs was not associated with common, mild acute infections in general practice, but was strongly associated with fatigue and psychosocial distress before presentation.
Which does not mean, as the authors hasten to note, that long covid is not real or “all in the mind” or purely psychological, but that psychosocial factors need to be considered: “there might be heterogeneous biological, psychological, and social factors engaged in triggering and maintaining the symptoms of the individual”.
The Back Page would also propose that if your definition of long covid encompasses 50% of young people turning up for a covid test, what you’ve defined there is the medical complication better known as “life”.
Sending penny@medicalrepublic.com.au story tips is a sign of high cognitive function.
