(ME) outbreaks can be modelled as an infectious disease: a mathematical reconsideration of the Royal Free Epidemic of 1955, 2020, Waters et al

Discussion in 'ME/CFS research' started by Andy, Jul 22, 2020.

  1. Amw66

    Amw66 Senior Member (Voting Rights)

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    Hmmm. A list of SW' s " mass hysteria" diagnoses and subsequent diagnoses would be interesting
    Camelford
    GWI
    9/ 11
    ......
     
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  2. Amw66

    Amw66 Senior Member (Voting Rights)

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    Modern farming methods in developing countries may be a link. Pesticide and herbicide use is often higher than recommended use ( organophospgates feature heavily) in the belief that more chemicals = more crop when in fact it negatively affects soil fertility over time unless you keep applying .
    Perhaps it us no surprise at increasing levels of arsenic in rice.

    Link to a study as background which looked at chemical use in rice farming.
    https://www.researchgate.net/publication/265404371_Farm_Pesticide_Rice_Production_and_Human_Health

    The farmers attitude is interesting, as is the health effects on farmers..

    I suspect that the cumulative combination of residual chemicals over the life of a crop has not been studied much and could gave significant impacts.

    It's not just a developing country issue , here the average potato crop is sprayed with a combination of herbicide and pesticide 32 times. Though there are targeted delivery methods ( satellite technology looks at leaf cover and senesence to enable dosing to be area specific ie only the plants that require it- this is done automatically via download to the tractor) very few farmers use it and just blanket spray.

    There was a paper a few years ago tracking hormonal issues in children in india to agricultural chemical use.

    Still looking for the toxic rice article.
     
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  3. Amw66

    Amw66 Senior Member (Voting Rights)

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  4. chrisb

    chrisb Senior Member (Voting Rights)

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    It is interesting to reread the Moss and McEvedy paper on the Blackburn School alleged hysteria

    https://www.bmj.com/content/bmj/2/5525/1295.full.pdf

    What became epidemic was a piece of behaviour consequent on an emotional state: excitement or, in the latter stages, frank fear led to overbreathing, with its characteristic sequelae-faintness, dizziness, paraesthesiae, and tetany. Once learned, this selfreinforcing piece of behaviour restarted spontaneously whenever the school was assembled. By day 12, however, the hysterical nature of the epidemic was generally accepted, and a firm line prevented the behaviour propagating as extensively as it had on the previous occasions.

    A
    question arises as to whether it was claimed this explanation was consistent throughout the alleged cases or whether the supposed cause of hysteria varied from case to case., suggesting that "hysteria" is just a word for whatever it is that happens.
     
  5. chrisb

    chrisb Senior Member (Voting Rights)

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    Strangely in the paper immediately following that last one

    https://www.bmj.com/content/bmj/2/5525/1300.full.pdf ยท PDF file

    Two School Epidemics McEvedy et al there appears to be no discussion of overbreathing as a causative factor. It seems to be all about personality factors.

    How soon we forget.
     
  6. Jonathan Edwards

    Jonathan Edwards Senior Member (Voting Rights)

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    I am afraid I think this paper tells us nothing useful. Nevertheless, all credit to the authors for getting something published and trying a fresh approach.

    The problems I see:

    1. The fact that some thought-to-be-hysterical outbreaks do not fit an empirically derived formulator infectious outbreaks does not imply that something that does fit is not hysteria. The argument does not follow. A mathematical formula for wings describes birds pretty well and not mammals. But it describes bats OK. As has already been said we would need evidence that hysterical outbreaks less than one time in a hundred, fit the infection formula. I also doubt that the infection formula is very robust. The complete failure of mathematical modelling of an epidemic to provide useful information in recent months highlights the problem!

    2. My memory of the M&B study is that they did not deny that there might have been an infectious outbreak. What they claimed was that the patterns of signs and symptoms that Ramsay had interpreted as evidence of encephalomyelitis in a small number of cases did not fit well with encephalitis. They suggested that instead these might be psychogenic. If psychogenic symptoms occurred as complications of an infection then that presumably would be entirely compatible with there having been an epidemic, for which overall figures would likely be typical.

    3. Although Ramsay thought there was evidence of encephalomyelitis the consensus now is that there is no evidence for encephalomyelitis in people with a diagnosis of ME as a whole. From what I can see M&B were very likely right about the signs not being right. Ramsay may have made a big contribution in getting the illness recognised but he was probably wrong about its nature and we should take that on board.

    4. Although M&B are charged with shifting opinion to a psychogenic view of ME I am not sure this is realistic. ME had probably previously been classified as psychogenic under neurasthenia or effort syndrome for 100 years. For sporadic ME, which is the majority, the mass hysteria versus epidemic debate does not even arise. What I think M&B did was to quash the idea that there is some specific epidemic encephalomyelitis illness about that can be used to explain ME. I agree with them that there isn't as far as we know.

    I think what is unfortunate about M&B's intervention is that they described what happened in psychiatric terminology in such a way that psychiatrists felt they could take ownership. The origin of the signs they described I would prefer to describe in terms of suggestibility. I don't think it makes sense to deny the existence of suggestibility in both patients and health professionals. The belief held by psychologists that CBT works for ME/CFS is ample evidence for suggestibility - the reality is that they cannot possibly know if it does base on their practice (as explained in my evidence to NICE). The belief held by patients that they are miraculously cured of ME by rituximab, the Lightning Process or various other methods that are unlikely to have and real effect on physiology indicates the same. But there is no reason to think suggestibility has anything to do with ME/CFS as we now understand it.
     
  7. chrisb

    chrisb Senior Member (Voting Rights)

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    The difficulty which this argument faces is that a number of cases were excluded from the paper on the basis that they were thought to be suffering "hysteria". This suggests that those cases and perhaps all the cases were properly assessed by a psychiatrist, better qualified than McEvedy and at least equally qualified to Beard. That non diagnosis was overturned merely on reading the notes and without experience of the patient, Is that any way to diagnose hysteria?
     
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  8. chrisb

    chrisb Senior Member (Voting Rights)

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    If suggestibility was the cause of the Royal Free "epidemic" what is proposed as the cause of the more sporadic outbreak in North West London which started before the Royal Free outbreak and finished after it (Compston 1978). What also was the cause of the Dalston outbreak occurring slightly earlier but unknown to those at the Royal Free.
     
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  9. Jonathan Edwards

    Jonathan Edwards Senior Member (Voting Rights)

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    I suspect that everybody agrees that it is highly likely that all these outbreaks were mini-epidemics of infection. The issue of suggestibility merely relates to certain patterns of symptoms picked out by Ramsay as indicating encephalitis which probably didn't. In an age when unknown infection raised the worry of polio the possibility of the clinical picture being clouded by suggestibility was quite likely to be a general but variable quantity depending on all sorts of more or less random contextual factors.
     
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  10. chrisb

    chrisb Senior Member (Voting Rights)

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    Yes, I agree with some of the difficulties surrounding encephalitis, but I don't understand the need to add the additional layer of suggestibility, for which there is no more evidence than there is for encephalitis, when the infectious epidemic in the neighbourhood is a possible explanation of all the cases.

    Myalgic encephalitis was something of a hostage to fortune allowing the likes of Straus and Eisenberg, enthusiastically followed by our BPSers, to call it a spurious disease construct, but that failed to explain away the facts.
     
  11. rvallee

    rvallee Senior Member (Voting Rights)

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  12. Trish

    Trish Moderator Staff Member

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    Do you mean Ramsay was looking for symptoms of encephalitis, so misinterpreted their real symptoms as suggesting that diagnosis? Or do you mean the patients were suggestible and somehow created symptoms that weren't real?
     
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  13. Jonathan Edwards

    Jonathan Edwards Senior Member (Voting Rights)

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    I am sure the symptoms were real. But it is easy to misinterpret realities. I suspect the main problem is that Ramsay thought he was looking for signs of encephalitis. On the other hand patients worried that they might have a polio like illness might have misinterpreted sensations.

    Neurological sensations are particularly easy to mis-witness, if you like. Think of the game where you twine your wrist around each other and someone asks you to move the finger they point to and you find you move the one on the opposite hand. The experimental psychologists have all sort of other tricks that prove the unreliability of our witnessing of nerve signals.

    But I really don't think it matters because ME has nothing much to do with these acute symptoms occurring during an episode of infection. It is an illness that comes afterwards and seems to have nothing very specific to do with any infection that might trigger it.
     
  14. Hoopoe

    Hoopoe Senior Member (Voting Rights)

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    Whatever one's interpretation, these outbreaks are given too much importance. While it's useful to know that outbreaks can produce a lot of ME/CFS cases, the number of patients that became ill during outbreaks is insignificantly small compared to the number of patients that did not.

    The Tahoe outbreak affected less than 200 people, while current estimates put the number of people in the US that meet diagnostic criteria for ME/CFS around 1-2 million.

    The real story is that there is a significant public health problem that is not being adressed.
     
    Last edited: Jul 24, 2020
  15. chrisb

    chrisb Senior Member (Voting Rights)

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    Does that really apply if the only reason for the original illness was suggestibility leading to a false belief in illness.? Where does that leave the patient when the illness continues?

    We have seen that SW carried forward from mass hysteria into sporadic ME the language of abnormal illness behaviour and maladaptive behaviour. Concede too much and they are left with this.
     
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  16. Sly Saint

    Sly Saint Senior Member (Voting Rights)

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    a few more interesting snippets from the little red book;
    eta: referring to Lake tahoe outbreak
     
    Last edited: Jul 25, 2020
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  17. chrisb

    chrisb Senior Member (Voting Rights)

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    Can that date of 1990 for the Oslo /Sweden polio outbreak be correct.? Does it mean 1890?
     
  18. Sly Saint

    Sly Saint Senior Member (Voting Rights)

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    Last edited: Jul 25, 2020
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  19. chrisb

    chrisb Senior Member (Voting Rights)

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    The original paper under discussion sent me back to look at McEvedy's papers on the schools outbreaks. It occurred to me that one might learn something not only from the rate of spread, but also from the rate of recovery.

    Both the Blackburn and RFH conditions were postulated on the ground that illness in a small number of original cases led to a fear of polio and a hysterical reaction in the remainder. It might be reasonable to suppose that once the fear was shown to be unfounded similar rates of recovery could be expected. There seems to be no report of delayed recovery in the Blackburn cases. According to Ramsey 75%, probably of those responding to his questionnaire, continued to have symptoms, some severe, 30 years later.

    His Two Schools Epidemics paper ends with

    A diagnostic category that is reached only by exclusion will
    collect all the errors made at earlier stages in the diagnostic
    process-and fall into disrepute. If diagnoses of epidemic
    hysteria are to inspire any confidence they must be made on
    positive grounds. Nevertheless, it does seem possible to collect
    positive data not only in the specially favourable case of mass
    admission to hospital but in the ordinary clinically undocumented
    instance.


    which rather suggests he wanted hospital data to prove his hypothesis.

    Edited-typos
     
    Last edited: Jul 27, 2020
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  20. Sly Saint

    Sly Saint Senior Member (Voting Rights)

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