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

Andy

Andy

Retired committee member
In 1970, two clinicians, McEvedy and Beard [McEvedy CP, Beard AW (1970) Royal Free Epidemic of 1955: A Reconsideration The British Medical Journal 1: No. 5687: 7-11] re-analysed some of the case notes, and hypothesised that the Royal Free outbreak was epidemic hysteria. This hypothesis was the beginning of an entrenched belief that the disease at the Royal Free, and similar cluster outbreaks, were psychosomatic. This was to have a profound effect on the interpretation of the same illness for nearly 50 years as a presumptive psychosomatic, an interpretation that has lasted nearly 50 years.

Methods : The 1927 Susceptible Infected Recovered (SIR) mathematical model [Kermack WO, McKendrick AG. Contribution to the mathematical theory of epidemics. Proc Royal Soc London. 1927;772:701–721] for the transmission of disease has been used to examine the published admission data from the Royal Free Hospital. for the purpose of finding out if the disease had the characteristics of a contagious disease. Similar cluster outbreaks have also been modelled to assess whether they have similar characteristics to the Royal Free outbreak.

Results: Using the 1927 Susceptible Infected Recovered (SIR) model [Kermack WO, McKendrick AG. Contribution to the mathematical theory of epidemics. Proc Royal Soc London. 1927;772:701–721] for the transmission of disease, we show that the epidemic of a disease of an unknown aetiology at the Royal Free Hospital in 1955, and other similar twentieth-century outbreaks, have the characteristics of a communicable disease. The disease causing the Royal Free outbreak was given the name ‘Benign Myalgic Encephalomyelitis' by Acheson [A new clinical entity? Lancet. 1956;1:789–790] in 1956, now identified as ME.

Conclusions : By showing that the Royal Free and other ME attributed outbreaks fit the SIR disease model, we demonstrate that the McEvedy and Beard hysteria hypothesis is mathematically incorrect. The ensuing management of the treatment of ME/CFS-like conditions evolving from that, now mathematically improbable belief may need to be re-evaluated.
Click to expand...
Paywall, https://www.tandfonline.com/doi/abs/10.1080/21641846.2020.1793058?journalCode=rftg20
Sci hub, https://sci-hub.tw/10.1080/21641846.2020.1793058
 
It looks like a mathematician with a family member with ME, and the other two are an engineer and an architect who are probably friends and they did it out of interest.

Edit: The organisation they all list, 'Time for Health, Cambridge' doesn't appear to have a web presence.
 
This looks to me like a very elegant approach.

On the one hand, you have McEvedy and Beard who simply read the medical notes from the 1955 epidemic - choosing not to contact either the patients or their treating doctors - and drew a conclusion that fitted their beliefs. That seems to be a method wide open to bias.

On the other hand, this new study looked for external evidence that would support either an infectious or hysteria basis for the 1955 outbreak. They extracted datasets for the Royal Free 1955 and other outbreaks, and a hysteria outbreak and looked to see if the data fitted the pattern of an infectious or hysteria outbreak.

I'm in no position to judge the validity of the models, though I do know that the SIR (Susceptible/Infected/Recovered) approach is widely used to model infectious outbreaks, including Covid-19/novel coronavirus (e.g. the Imperial College coronavirus model).

However, the approach of looking for new data that would throw light on the question is refreshing.
 
I hate to sound negative, but I would be careful to cite this paper. The analysis is interesting and they raise some valid points, but the conclusions are not supported by the data.

The relation between gamma and beta in the least-square fit will depend on the time window where the fitting is made and also on the number of people at risk (N in the paper). It is not clearly specified how these values are chosen. The fact that you don’t have a minimum in Figure 6 may be caused by too short a time window in the analysis.

Moreover, the peaks in the Royal Free epidemic that are indicated with arrows in Figure 2a do not necessarily reflect separate outbreaks. The SIR model is continuous and assumes an exact incidence and recovery rate. In a more realistic approach, these rates should be modelled as a probability per unit time to become sick or well. When you include such stochastic aspects into the model, the different epidemics vary a lot in length and number of affected people also when the gamma and beta parameters are kept constant. In the Figures below, I show the results of two simulations with identical parameters but with rate modelled as probability per unit time and the number of people actually affected decided by a random number generator. The second example has the appearance of two or three separate outbreaks, but these variations are only due to chance.

Most importantly, the authors should explain which qualities in Figure 6a that cause the absence of a least-square minimum. I believe it is a bad choice of the simulation window, but the rapid variations of the incidence—for example during days 7, 8, 9, 10 and 11—contribute to a poor fit. That may be caused by a combination of poor reporting and chance. There are no cases reported during day 10 and 11, nor during day 17 and 18. These blank spots are exactly one week apart.

I think that the authors miss an important point. Epidemics attributed to mass hysteria are typically short in duration, at most two or three weeks. This also applies to the Kombolcha outbreak that is studied in the paper. The ME outbreaks, on the other hand, lasted for several months. Hence the duration suggests that the ME outbreaks were not mass hysteria.

In conclusion, modelling of ME epidemics is interesting, but I think this paper leaves many unanswered questions.

upload_2020-7-23_9-7-21.png
upload_2020-7-23_9-7-37.png
 
I don't think a believer in mass hysteria would be convinced. Comparing an (alleged) outbreak of mass hysteria among young girls in Ethiopia in 2013 with another outbreak in a hospital in 1955 England doesn't seem like a good comparison. A believer in mass hysteria would say that these outbreaks differed because the social and cultural environment was very different.

I doubt that in the Ethiopia outbreak, there were the resources and knowledge to properly test for environmental factors.

Mass hysteria is not really a scientific concept because it's not possible to prove or disprove. We just assume it exists because we can't find an explanation for some events, and we assume it's not present when we find an explanation.
 
Last edited:
Amw66 said:
do we know the Eithiopian outbreak was mass hysteria - there was a recently labelled outbreak ( with hallucinations etc) which was found to be due to rice that had been eaten ?
Click to expand...

Can you tell us more about this (the rice in particular)? Was it the alleged mass hysteria in Malaysia?
 
From Byron Hydes Little red book

Colin McEvedy: June 6,1930-August 1, 2005
Mr McEvedy was working on his MA at Magdalen College, Oxford when he initially
gained recognition by publishing a thesis based upon two reputed instances of mass
hysteria that occurred in two primary schools in the United Kingdom. It would appear
that no one checked his sources and so I assume that a similar approach must have
looked like an easy way to get a PhD.
In a court case before Justice Macpherson accordingly, either McEvedy or his tutor Dr.
Alfred Beard suggested that his PhD thesis would be on a similar case of mass hysteria.
It is obvious that Dr Beard and the then Mr McEvedy had already decided that the
Royal Free epidemics were cases of hysteria well before they examined the evidence.
Accordingly, as in the cases of the two girl schools, there was no need to waste time by
actually examining any patients.
In fact, in a case heard before Justice Macpherson on Monday 26th of June 1989, the
lawyer Mr. Beckman, referring to a patient, asked psychiatrist Alfred Beard:
Q. Did you then examine him?
Dr Beard replied:
A. A psychiatrist does not ordinarily conduct a physical examination.
So, in 1970 when McEvedy used the London Royal Free Hospital epidemics as a basis
of his PhD thesis it was understandable, working on a similar theory as his tutor,
there was no need to actually examine anyone or for that matter, even take a history of
any of the actual Royal Free patients.
Click to expand...
"The episode at the Royal Free Hospital (a teaching hospital in London,
UK) also affected nursing and medical staff. It took place in 1955. On 13th
July of that year a resident doctor and a ward sister were admitted as inpatients
at the start of an epidemic that eventually affected almost three
hundred members of staff.
The commonest symptoms were: profound malaise, headache, low-grade fever, sore throat, nausea, severe depression, swings in emotional state, dizziness, vertigo, and neck-, back-, limb- and chestpain.

Signs included generalized enlargement of the lymph nodes, particularly those in the neck (cervical lymphadenopathy), and muscle changes such as 'fasciculation' (in which the muscles appear to show a rippling motion), spasm, twitching and tingling. In most patients there was clinical evidence that the
brain and spinal cord were affected. About a quarter of the patients had problems with their urinary bladder. On physical examination, the liver was enlarged in about a tenth of the patients. In general, the illness became worse during the second and third weeks after clinical onset".

In addition to the obvious physical and neurological signs there were
abnormal EEC's. These facts did not seem to deter McEvedy.
In spite of the clear physical symptoms and signs just noted, Colin McEvedy who
attained his PhD on the basis of his research at the Royal Free and Dr. Alfred
William Beard published their "scientific paper" in the British Medical Journal in
1970 that drew a quite different conclusion.
Click to expand...
The Two Mass Hysteria School Epidemics
I first attempted to interview the school principals in charge of the two schools where
the reputed two hysterical epidemics occurred. You will recall that McEvedy
obtained his MA for research on his documentation of these epidemics that he termed
hysterical.
Still in the UK, I telephoned the two girls schools where the epidemics had taken place
on which the then student, Colin McEvedy, based his first two cases of mass
hysteria.
...
I did succeed in speaking to the head mistress of the second school. Even though it was
well over ten years since the McEvedy incident she was still quite angry with him. She
recalled the incident in great detail. She said that Dr. McEvedy had never been to the
school, had never examined any of the children and that his thesis was a work of total
imagination.
Click to expand...
How did McEvedy come to his conclusions then? Dr. Ramsay stated that Dr.
McEvedy was given permission by medical records to look at some of the charts
and after a few hours he left never to return. McEvedy then wrote up his thesis for
which he obtained his PhD.
This tells one how easy it was to obtain a PhD at Oxford at that time. In other
words, no real research was done, no examination of patients was ever performed,
no in-depth investigation of the records was ever undertaken and according to Dr
Ramsay, no staff physicians were ever interviewed. Worse, no person at Oxford or
at British Medical Journal appears to have ever questioned the veracity of this
totally bogus research.
Click to expand...
I asked Dr. McEvedy did he have any records concerning the two schools he had
reputedly visited? He said he did not.
"Why had he written up the Free Hospital epidemics as hysteria without any careful
exploration of the basis of his thesis? I asked.
His reply was devastating. He said, "It was an easy PhD, why not."
Click to expand...
https://www.imet.ie/imet_documents/BYRON_HYDE_little_red_book.pdf
 
If one thinks through that court exchange one might come up with interesting hypothoses. Why would counsel have been cross-examining Beard in such terms? Presumably because he had provided an "expert opinion" for the defence. Who would "The Defence" be? Presumably an Insurance Company. One wonders what insurance company. One of the largest insurance companies was taken over by UNUM round about that time. I used to know which.

I think it was in his obituary that it was observed that he liked to spend time with his private practice.
 
Interesting study.

The mathematical modeling is above me but what I would like to see is a probability: how unlikely is it that random data fit the SIR model as the data from the 1955 ME outbreaks did? I suspect this is possible to do, using some simulations.

It is also unclear if the SIR model can be used to differentiate outbreaks from an infectious disease with outbreaks that are due to ‘hysteria’ or something else. One could, for example, take data on several infectious outbreaks and data from what are believed to be‘hysterical’ or other outbreaks and give them to blinded statisticians and see how well they can classify them based on fit to the SIR model.
 
Toxic poisoning can happen much more easily than one would expect. All that needs to happen is a farmer being distracted for a moment or choosing the wrong product. We all have made errors like these.

Another way for it is to grains being affected by fungal toxins while in storage. And probably there are many other ways.

Toxic poisoning cases might be overlooked when they aren't severe enough and don't occur in clusters. In the Aldous paper, the poisoning was discovered because by chance, it happened to affect many people at once and because some effort was put into investigating this possibility.

In countries like Ethiopia and Malaysia they might not have resources to investigate the toxicological angle.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom