HISTORY OF MEDICINE: A Plague of Confusion

This article has been slightly expanded upon to provide clarification for those unfamiliar with the epidemiology of the three plague pandemics - which resulted from different strains of the same bacterium.  A few additional edits have been made for the avoidance of confusion by non-specialists in palaeopathology and the archaeology of disease, and to update the article in line with what is currently known about the recent cases in China.

It was around 2:00 am when my attention was drawn to a video put out by Bloomberg Tiktok – produced by Matthew Albani and shown below.  The video is a response to news of cases of 'plague' in China in recent weeks.

Is the plague making a comeback? pic.twitter.com/Hj6DdltGEf

— Bloomberg TicToc (@TicToc) November 20, 2019

Because it was 2:00 am I couldn’t express my initial response out loud without waking my neighbours.  Another video replete with misunderstandings, conflations, and a tone in line with other Irritating STEM Bros™ (a term stolen from my colleague Dr Joanne Edge who coined the phrase in this article) such as Neil DeGrasse Tyson and Steven Pinker.  This was personally frustrating on many levels, in part because as someone who works at the intersection of archaeology, history, and pathology this is an area I know well, but also because so many scholars have been attempting to quell this plague of misunderstandings for years with little success.  This post explores what is correct, along with the numerous errors, conflations, and confusions.  A TL:DR is provided in bold at the end.

Let’s start with the few things this video gets right in context.  There have been cases of plague in China.  There have also, as it states, been a number of cases in the United States of America every year.  This is normal, and treatment is relatively simple (caveats apply which we will come to later).  The preconception that the plague is a historical thing (I refuse to comment on the sneering tone used when talking about ‘history class’) is in fact predicated on the terminology used in this exact video.  The last outbreak of bubonic plague in the United Kingdom was during the early part of the 20^th Century – a localised outbreak in Freston, Suffolk – though the diagnosis is disputed.  However, all of the terminology and all of the imagery used in this video conflates and confuses centuries of history, before engaging in a typical Irritating STEM Bro™ comment on medieval medicine.  It is also worth noting that not one element but all of the relevant correct information and research can easily be found and double checked in less time that it would have taken to make the video. 

Plague – Antiqua, Medievalis, Oreintalis, Pneumonic, Bubonic, and Basic Distinctions.

Yersinia Pestis - in an image created through scanning electron microscopy

First let’s look at what might be called the ‘science’ bit.   The most frequently repeated word in the video is ‘plague’.  The problem is that while a single pathogen – Yersinia pestis – is the most probable cause of the Black Death, the same single pathogen caused 3 strains of plague which resulted in several forms with various symptomologies – the most notable being bubonic, pneumonic, and septicemic.  The statistic presented – that death occurs in only 7–10% of cases – is inaccurate – even if we take all three primary forms as a whole, and it is worth noting this is only with treatment.  Without treatment bubonic plague is fatal in approximately 80% of cases.  However, pneumonic plague is more dangerous without treatment.  Access to treatment is significant – and it is worth noting that the rarest of three main forms – septicemic – can be fatal without any symptoms.  

Yersinia pestis is generally accepted as having caused three pandemics – each resulting from a different strain of the bacterium.  Y. p. antiqua – which was the cause of the Plague of Justinian, discussed further below, Y. p. medievalis, which caused the Black Death and subsequent epidemics; and Y. p. orientalis – which caused the third plague pandemic and subsequent outbreaks.  Of these the genomic sequence for only two is available – that of Y.p. medievalis and Y.p. orientalis. [Information on these can be found in - Achtman, M; Zurth, K; Morelli, G; Torrea, G; Guiyoule, A; Carniel, E (1999). "Yersinia pestis, the cause of plague, is a recently emerged clone of Yersinia pseudotuberculosis". Proc Natl Acad Sci USA. 96 (#24): 14043–14048. Bibcode:1999PNAS...9614043A. doi:10.1073/pnas.96.24.14043. PMC 24187. PMID 10570195.]

There is still a degree of debate over whether each individual strain was capable of producing all forms of the plague, whether some were more likely to produce one or two distinct forms, or if the resultant form was largely dependent on the route of transmission as with Y.p. orientalis.

In the later part of the video a comment is made about ‘locking away [our] families’ – however, quarantine is a very important defence against plague transmission, particularly in cases of pneumonic plague.  While antibiotics are effective, there are risks – and the use of antibiotic treatment for cases of plague in animals a potential issue.  Effective use requires cases be treated according to different protocols.  In the case of animals euthanasia and secure disposal are considered the only truly effective methods of preventing the spread of the disease.  While vaccines have been developed, they have proven to be ineffective.  Alongside this there is the looming, and frankly terrifying, possibility of the development of an antibiotic resistant strain which resulting in any one form could have a devastating impact – particularly if it were to primarily result in the pneunomic form since it becomes aerosolized and therefore in a limited manner airborne.  The cavalier attitude towards infection control is perhaps an example of the naivety created by the belief that modern medicine is not only superior to the medicine of the past, but also infallible.  I would argue that the battle against antibiotic resistance is in some ways made more difficult by this exact belief – resulting in people not completing treatment, and furthering the spread of the pathogen through contact with others because of such a view.  A t the other extreme the anti-vax movement shows how distrusting some have become of medical science.  In either way the plague is not something which should be treated so lightly. 

Additionally, it is worth emphasising at this point that the case in China is of pneumonic plague specifically (at least according to Chinese sources) – however news sources aimed at adults and children have reproduced information concerning the bubonic form of the plague instead - with no details on the bacterium or that it can result in three or more forms of infection.

  

When is the Black Death not the Black Death?

Doctor Beak: The common image of the beak masked plague doctor in fact comes from the 1600s - while part of the same pandemic, this is 200 years after the period usually referred to as the Black Death.

In addition to being wrong about the statistics, and conflating significantly different strains of the pathogen, the video is also almost universally wrong when it comes to the plague in the Middle Ages – specifically the Fourteenth Century outbreak commonly referred to as the Black Death. 

In term of epidemiology the Black Death is usually considered to be the ‘second plague pandemic’, the ‘first’ being commonly referred to as the Plague of Justinian in AD 541-542.  Notably in 2013 both were identified as being the result of Yersinia pestis, and while is generally accepted that the Plague of Justinian killed fewer individuals, the total impact was still the reduction of the European population by between ¼ and ½ of its previous level.  In terms of identifying the most likely form  it is generally considered that it was pneumonic plague which was the primary culprit – although bubonic plague also occurred.  Giovanni Boccaccio, writing in the Decameron, gives us an accurate description of the symptomology with the sole exception that the buboes (swellings of the lymph nodes) are not an indicator that the individual is certain to die.  Lodewijk Heyligen writing in the 1340s also gives us a description which is consistent with pneumonic plague – which is now considered the primary driver of the pandemic in humans.  It is worth highlighting that the statistics referred to either relate to bubonic plague, or to all forms, not specifically to pneumonic, which is the form involved in the cases in China which sparks this video.

The term Black Death – ‘mors nigra’ in Latin – is generally a later epithet for the outbreak – it is used in 1350, while the term ‘artram mortem’ appears to have been used in the Seventeenth Century to refer to the Fourteenth Century outbreak.  The term ‘atra mors’ was however in use as a term for pestilential fevers much earlier – appearing in the works of Gilles de Corbeil more than two centuries earlier.  It is not used directly in the sense meant here in English until 1755.  Contemporary sources simply refer to a Great Plague.  This could be compared to the change between the Great War / World War 1.  This specific term however highlights another area where the video is both sadly, and perhaps somewhat shockingly, inaccurate.  While both the Black Death and the plague in the 1660s (including the plague outbreak in England in 1664-5) fall under what is termed the ‘second plague pandemic’ – which covers its migration from its purported origin in Kyrgistan via Mongolia, China, to the Middle East, to Genoa, and subsequently throughout Europe – the two occurred in distinctly different cultural contexts.  This is where the majority of the historical inaccuracies fall since all of the imagery of the medieval plague displayed – particularly the appearances of the legendary Doctor Beak of Rome (a common name for the stereotypical plague doctor with the classic beaked mask) – are drawn from the later.  The 1660s outbreaks took place against a background of medicine loosely based on the miasma theory of disease transmission – where ‘foul air’ / ‘vapours’ etc were considered to be responsible.  It is worth noting that pneumonic plague is aerosolised / airborne in transmission, so in some senses protecting airways and avoiding breathing in air around the infected is perhaps as not as unwise as it is made out – given current quarantine procedures for airborne infections.  The Black Death took place against an entirely different medical background – that of humoral theory which had been transferred back into European medicine from its Greco-Roman origin, via Avicenna (Ibn Sina)’s The Canon of Medicine in 1025.  These two contexts resulted in entirely different approaches to the treatment and containment of the pandemic.  They are commonly conflated, with the Doctor Beak image being the most common icon or symbol of the Black Death despite the three hundred year gap between the two.  However, the fact they are commonly conflated is also widely known. 

Myths about Medieval Medicine

Constantine the African examining urine samples - a commonly used representation of medieval medicine.

The final frustration is of course the closing statement about how ‘people in the 14^th century rubbed snails on themselves to heal burns’.  While I haven’t had a lot of time to check my records, since the video gives no indication of where this claim comes from, I can’t comment on its exact historicity.  It is notable that medieval medics did use some unusual and ineffective methods of treatment.  These were based on how things were perceived and there was a degree of evidential enquiry.  Saying that medieval medicine is crude compared to modern standards would arguably be about as accurate as someone from the future calling our medicine primitive, since we carry out operations using surgical tools made from steel and titanium rather than using multifunctional nanomachines developed in the Twenty Second Century.  It is realistically a completely pointless comparison.  Medieval medics attempted to diagnose conditions based on observation, and existing theories of how the body, and indeed the world, worked.  It may be true that snails were used to treat burns – indeed it is a notable fact that medicine from animals was as prevalent as medicine based on plants, both steadily transitioning to chemical based pharmacology over time.  However, in the Twenty First Century we still use dishes smothered in crushed algae (agar), and take medicines wrapped in a by-product of boiled and rendered pig skins and cow bones (gelatine).  As with the sadly ever present repetition of the frequently discredited term ‘Dark Ages’ by science bloggers and personalities, medieval medicine is reduced from what is known to its most irrational sounding forms – which can be done to any subject or argument in order to make it sound absurd.  There are examples of human behaviours in any society which sound strange from an outside perspective – this is as true of current societies as it is with societies in the past – the reality is that our views are intrinsically linked to the praxis and mores of the society in which they originate.  Medieval medicine may not make sense to us, but modern medicine may equally not make sense to future societies.  Ridiculing past medicine as a way of allaying fears of a plague which in the past may have killed over 300 million people (based on best possible estimations related to population size and subsequent effects) is a somewhat ridiculous effort, especially when considering the numerous conflations in the historical evidence, and errors of identification in the scientific evidence. 

An increase in cases of bubonic or pneumonic plague is a cause of concern – and while perhaps not as immanent a concern as the Artic wildfires of the summer of 2019, or the current (November 2019) wildfires in Australia, or indeed the reduction of the world’s levels of drinking water, or an epidemic of any form of viral hemorrhagic fever (Ebola, Marburg virus, RAVN) – it is still a serious concern.  An antibiotic resistant strain of any form of plague could have a devasting affect.  It is worth noting that in addition to its existing as were ‘in the wild’, bubonic plague was one of the earliest diseases to be weaponised in both China and Medieval Europe, as well as during World War 2, and pneumonic plague was particularly experimented on, including genetic engineering by the Soviet Union during the Cold War.  While such weapons are banned by various international treaties, as events in the recent conflict in Syria have shown such treaties, naturally, can be broken by states and non-state actors.   

The pathogen – Y. pestis – is a concern, particularly considering the growth of antibiotic resistant strains of other bacterium.  It is worth noting this is a small number of cases, beginning with an individual who contracted the pathogen apparently through animal contact (eating infected meat from an animal he had caught), and it is not even realistically a large outbreak, much less an epidemic or a pandemic, and is certainly not on the scale of recent incidences such as those involving Ebola.  However, it is worth noting that in complete contrast to the attitude to medieval medicine displayed in this clip, in the last ten years, a modern, highly resistant pathogen – MRSA – which has killed many people in modern hospitals under the care of modern medicine – has been found to be fatally weak against a medieval eye salve recipe.  Perhaps it is worth considering that given the high cost of book production – which can be seen simply from the vast array of scribal abbreviations used to save space – anything written down was written down for a reason.  Unlike today, where tweets fly around the world with barely a second thought, and the tap of a screen, in medieval society if it was written down it had to be worth the time and skills of a limited group of individuals.  As such there is a possibility that any of the methods described, and any of the medication recipes preserved, was considered worth preserving – and therefore most must have been of some use to a certain extent.  While our knowledge is limited due to the issues of survival and preservation, it is possible that further investigations along the lines of the AncientBiotics project, may make discoveries, especially combined with other potential forthcoming projects which will enable access to a greater body of data with which to explore the spread of certain pathogens. 

Medieval medicine may be mocked by Irritating STEM Bros™ - but its goal was the same – saving lives.  I don’t believe that should be mocked, and I believe that both culturally and scientifically, the past, both the medicine and the world view, can help us to understand how we got we where we are, and may help us in the future. 

TL:DR – The video mixed up the 1600s and the 1300s – using images from the former about the later.  The statistics used are for all types of plague or just bubonic, not pneumonic which it is actually reporting about.  It’s wrong about the Black Death in general, getting lots of details wrong, and making unfounded assertions about medieval medicine.  The original story is about a single case of pneumonic plague, which is treatable, and has only caught the world’s attention due to the sensationalising of elements relating to the Black Death, which have become a staple of some forms of horror fiction in the last 10 years, and a current hyper-awareness of pandemics, mostly reflected in popular culture's growing interest in a zombie apocalypse - but also through the recent outbreaks of Ebola.  News stories have reproduced info about a different strain of plague, causing more confusion.  As a result Irritating STEM Bros™ have taken the opportunity to ridicule medieval medicine – without acknowledging that it was simply working with the evidence it had, being a complex product of its time, just like modern medicine.  In short, while there is no reason to be concerned that the medieval strain of plague is making a comeback, there are reasons to be concerned about the potential for pandemics in an increasingly interconnected world, just as there with climate change.