News about Long Covid including its relationship to ME/CFS 2020 to 2021

RT-PCR tests have varying reliability. For example their sensitivity depends on time passed since infection onset.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7240870/

It's also possible that the tests are especially unreliable for long covid patients because their expression of the illness is not the reference for which the tests and testing guidelines were developed.

 

I don't quite see why patients who will later go on to develop long covid or ME/CFS after COVID-19, would have much higher rates of false negatives on PCR testing?

 

Yahoo!life : A COVID-19 long-hauler details his year of 'hell'
Senior Editor Ed Hornick got ill with Covid-19 over 10 months ago and shares his story. Mentions ME a couple of places.

I've wondered why Yahoo!life has had some rather good, in depth articles on Long Covid.

 

I can see how it could easily happen in various ways, but it's a bit complicated to explain and some speculation is involved. It has a lot to do with systematic bias and nonuniformity of the illness.

The idea is that covid-19 is expressed differently in every person, depending on factors such as age, gender, immune response profiles, and others. A good example is that in children it's often quite different than in 50 year olds. But we discovered that only later because society first pays attention to the more obvious expressions of covid-19. We saw that early in the pandemic, covid-19 was presented as a respiratory disease in older people. Then we became aware it was also a problem in younger people. Then we discovered it in kids where it was very different than in adults. We also became aware of long covid and many of these patients and it appears that these are often more impaired months after a mild illness than people months after a severe illness.

If guidelines for doctors are written with the "severe illness, hospitalized patient" patient in mind (a form of bias), that could lead to many people with initially mild illness to not seek or be offered tests with the same urgency as other patients. That could in turn affect test positivity rates, for example via differences in the timing of testing which as we've seen is crucial in RT-PCR tests.

Tests are also being developed with a reference patient population and it may quite likely be a sample of predominantly a 40-60 year old men with acute and severe illness who were hospitalized. Test sensitivity may decrease the more a person falls outside this patient population. Some of the data mentioned earlier suggests this.

(there is more but I don't want to mentally exert myself more at the moment)

 

don't know if this has already been posted
https://twitter.com/user/status/1359598165167644676

 

Thanks for explaining it (although I'm not very convinced by the explanation)

 

I doubt they are going to listen.

But I'd suggest a creative look at vascular and endothelial function, particularly peripheral muscular (and brain) capillaries. And I don't mean a superficial look that claims everything is fine because they haven't found obvious (severe damage)* or nothing is wrong when looking at a small subset of inflammatory markers or cytokines. *(it turns out the people with severe vascular damage often die, who would have known?)

In terms of the virus itself, researchers need to look beyond the superficial - it is more than the presence of ACE2 receptors that predicts lesions in a particular type of tissue. Similarly, measuring inflammatory markers in circulation tells us very little about what is going on in specific tissue.

 

https://twitter.com/user/status/1362476920697458691

 

There should be some mechanism for the patient community to input into the policy re funding research. E.g. in this case to highlight the previous (negative) experience and how things should be done now.

Your suggestion re "vascular and endothelial function, particularly peripheral muscular (and brain) capillaries" sounds interesting. I would have thought there would have been some research into this e.g. re vascular dementia. What techniques are used --- are new techniques required or are the existing techniques (MRI ---)/technologies suitable?

@Michiel Tack

 

Interesting discussion. The HIV Disability Questionnaire was mentioned as an example of something that is capable of capturing fluctuating and intermittent symptoms (like PEM). I don't suppose anybody has access to that, and can let me see it, or point me to a link? @PhysiosforME ?

 

lower. they were 79% sensitive in men. So it's different, but not bigly, as a former president used to say.

 

From overviews it appears interesting but because, I guess reasons, it's copyrighted so it's hard to assess. Most health questionnaires are copyrighted. And cannot be accessed because of said copyright. Normal things. The incentive system in medicine is completely broken, essentially built for maximal paralysis.

https://research.mcmaster.ca/industry-and-investors/hiv-disability-questionnaire-hdq/

 

With a bit of work, I’ve managed to get many if not most questionnaires I wanted. Basically, when they are discussed often a sample question or two is mentioned. Putting strings into Google often results in either the questionnaire or more sample questions. Often the full questionnaire turns up in the appendices of a thesis.

 

Bear in mind @Andy that there's a review of questionnaires versus activity monitors (it's available somewhere on this site) and it found questionnaires overestimated activity; the activity monitors used were pretty sophisticated [time spent upright etc.]. This publication might be interesting if it compared the questionnaires with activity monitors, but I doubt it did.

Plagurising @Jonathan Edwards again:
"Subjective measures as listed are important to the patient but they are of no value as evidence. Outcomes of value would include actimetry, walking times, return to work, level of benefit requirements, NOT questionnaires."
[https://www.s4me.info/threads/membe...e-cfs-guidelines-draft-scope.4816/#post-86637]

Possibly there wasn't enough funding to use high quality actimetry [time spent upright etc.]. However, even if they didn't have much funding, I recall a US Army study (post conflict veterans) which used data from their mobile phones --- GPS to see if they are moving around etc. I guess. So there may be basic workarounds for studies which don't have a lot of funding [Fitbits?].

The other thing is that if the study is flawed, i.e. doesn't have objective measures, then I think it shouldn't be published - there's low confidence that the conclusions are correct.

 

Excuse me coming back to this @Snow Leopard I'm thinking of the interests of the ME/CFS community here! Do you think:
"---vascular and endothelial function, particularly peripheral muscular (and brain) capillaries ---" would be useful for ME/CFS?

 

While I don't disagree, my interest is less in its potential use in a research study and more for its possible potential in helping to identify fluctuating and intermittent symptoms for clinical and/or disability assessment settings.

 

If anyone gets hold of the HDQ, please let me know.

 

Covid-19: Recognise long covid as occupational disease and compensate frontline workers, say MPs

https://www.bmj.com/content/372/bmj.n503

 

A short attack of severe hubris gave me the idea to "just write a quick e-mail" to the contact given on the website found by @rvallee: https://research.mcmaster.ca/industry-and-investors/hiv-disability-questionnaire-hdq/

On a serious note, why not ask them to provide the HDQ to patient stakeholders and members of a NICE guideline committee?