Using Historical Texts to Investigate Disease in the Past

When I was doing research on rickets for my masters thesis, I used a lot of primary texts from the 16th to 19th century. These were primarily medical or government texts, and were written for a number of purposes. The goal of my dissertation was to compare osteological evidence of rickets against the historical record during the early modern period in London (late 16th to early 18th centuries). From contemporary texts there is a reported rise in a new disease, and the Bills of Mortality report that rickets is increasingly a cause of death during this period. My hypothesis was that there was a much higher prevalence of rickets in this period than we were finding based on skeletal remains alone, and therefore should seek new methods of diagnosis. In order to argue this, the historic text becomes a critical line of evidence.

A new article from the International Journal of Paleopathology discusses the role of historic texts in understanding disease in the past. Mitchell (2011) argues that there are a number of hazards that new to be recognized when studying using texts. While it is often thought that descriptions of disease come primarily from medical experts, there are a variety of sources that would record outbreaks and pathologies including histories of the era, epics and tales, biographies, personal letters, diaries, legal documents, religious proclamations, in additions to hospital and medical records. Bias and information can enter the text a number of ways. Different medical beliefs change the perception of the function of the body and what is considered normal. Information may be mistakenly borrowed from earlier documents when a disease or pathology is new to an individual. Also, the text may have been written with a slant in order to create a change, such as political documents arguing a disease was prevalent for a reason that personally benefitted them rather than the actual cause. Finally, just as today, misdiagnosis and misperception was fairly common. Often common sense, word of mouth and rumor were considered to be viable evidence in diagnosis and determination of prevalence. Often the social diagnosis of a disease is vastly different than the biological reality.

John Bell (1763-1820) [anatomist; artist], Engravings of the bones, muscles, and joints, illustrating the first volume of the Anatomy of the Human Body. 2d ed.; London, 1804

What further complicates understanding disease in the past through texts is that researchers are attempting to apply their own medical knowledge to give a retrospective diagnosis. Mitchell (2011:82) argues that “it is clear that retrospective diagnosis cannot be attempted for a large proportion of past disease descriptions found in written sources where the evidence is simply not specific or sufficiently detailed”. We cannot assume that the diseases present today are representative of the diseases of the past, nor can we assume that medical terminology has stayed the same. Researchers also need to determine whether medical texts are representative of the original body of texts, and of the social and medical perceptions of the time period. Often a number of different diagnoses were available, complicating modern determination of what the actual pathology was. To make matters more complicated, a lack of textual evidence does not mean that a disease wasn’t present.

In order to create more probably retrospective diagnoses, Mitchell (2011) offers a number of ways to avoid the pitfalls he discussed above. First, researchers must gather as many first hand testimonies of the disease as possible. Second, more reliable texts will have clear descriptions of symptoms, signs of the disease and pictures. When first hand accounts have recurring descriptions, it is more likely that the text is representative of the pathology. Third, the researcher needs to pay careful attention to locations and nature of the lesions and symptoms. Fourth, the cultural and social context of the author needs to be determined, as well as any factors that may bias their interpretation such as government or religious positions. Finally, in order to make a retrospective diagnosis there needs to be a clear and diagnostic connection between the modern and historic symptoms and signs.

When conducting my own research on texts from the early modern period, I ran into a number of these pitfalls that needed to be taken into consideration. A number of texts from medical experts and noted citizens in the 17th century recorded similar, but not directly copied, accounts of a disease which caused the bones in the arms and legs of children to soften. Unlike some more personal accounts, none of these attributed the disease to political, social or religious causes which may have shown a bias. An account from 1706 was suspect for stating the claim that every child was effected by the disease, a claim that no previous treatise had noted. Further inspection found that the individual was writing specifically for the king, and writing in favor of decreasing pollution which he argued would also decrease rickets. The only quantitative record of the prevalence of rickets comes from the London Bills of Mortality where rickets was recorded as a cause of death from the early 17th to mid 18th centuries. These numbers are problematic because one doesn’t die from rickets, and the individuals recording the cause of death were untrained laywomen who also recorded worms as a cause of death. By taking into account modern diagnosis and comparing this against the reliable historical texts, I was able to track the rise and fall of rickets in the early modern period. While texts are a valuable piece of information, they must be used carefully.

Works Cited

This post was chosen as an Editor's Selection for ResearchBlogging.orgPiers D. Mitchell (2011). Retrospective diagnosis and the use of historical texts for investigating disease in the past International Journal of Paleopathology, 1, 81-88

For more images of medical texts, check out the Vaulted Treasures Historical Collections at University of Virginia.

5 responses to “Using Historical Texts to Investigate Disease in the Past

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  3. We still get occasional cases of rickets in England.

    Here’s a very recent report of one baby born with undiagnosed congenital rickets from which it died after 18 weeks and this led to the parents being accused of killing their baby and to the removal of their second child for its protection from supposed child abuse. Fortunately they were acquitted and their second child was returned.

    During much of the year in Britain people, especially Black people, are unlikely to synthesise enough vitamin D through skin exposure to sunlight, because of our northern latitude. The same congenital rickets problem happens in e.g. Norway.

    Pregnant women and nursing mothers need to take Vitamin D supplements.

  4. Sadly, Mr. Morley is not aware that congenital rickets is so rare that there are fewer than 10 cases reported in the last thirty years. There is a anti-scientific theory claiming that Vit. D deficiency (a real disease) is the culprit in many cases of suspected child abuse. But there is no evidence that children with marginally low Vit D. levels suffer from weaker bones. There is real rickets in the 21st century. However, there are no cases of patients with true rickets ( a diagnosis that requires a full understanding of the Calcium, phosphate, PTH, and Vit D levels) that have a normal radiographic appearance. The lay press have continued to spin this pseudo-scientific theory about rickets, but there are no peer reviewed case reports or studies of this disease that have upheld this concept.

  5. Thanks Brent, but I did not say congenital rickets is common, I said we still get ‘occasional’ cases.

    You seem particularly keen to rubbish an “anti-scientific theory claiming that Vit. D deficiency … is the culprit in many cases of suspected child abuse”, and that “there’s no evidence that children with marginally low Vit. D levels suffer weaker bones”.

    However if you read the report more carefully, this case was of *severe rickets* and, while the news report does not give the precise vitamin D level of baby Jayden, it does report breast feeding “made his condition worse because her [the mother’s] own vitamin D levels were so low” – so this case does not appear, as you suggest, to be about a “marginally lower vitamin D level”.

    This case involved whether it was possible, or not, to detect rickets in a weeks old baby radiologically; I have no idea what your evidence is for suggesting this is always clearly apparent in such cases.

    However the news report told us an “independent review of radiology issues arising from the case [was conducted by] by Dr Stephen Chapman, of Birmingham Children’s hospital. This said: “It would have been best practice to raise the possibility of an underlying bone disease in the report (eg. vitamin D deficiency/rickets) …” but concluded that it was “not an obvious case of rickets”.
    Therefore his expert evidence to the Court was that rickets is NOT radiologically apparent in a baby a few weeks old.

    However this was disputed – a former GOSH [Great Ormond Street Children’s Hospital, London] paediatric radiologist, Karen Rosendahl, [consultant paediatric radiologist at Haukeland University hospital in Bergen, Norway], disputed that, in general, cases of rickets were necessarily hard to detect on a survey. She told the Guardian: “It’s very often not particularly difficult to see but you need experience. It’s complex. You need five to 10 years of experience to get the diagnosis correct.”

    She is not saying, as you appear to suggest, that rickets is clearly apparent radiologically in paediatric cases, but paediatric cases need several years of experience to detect radiologically.

    I would hesitate to contradict the findings of a judge who has heard the evidence from a range of medical experts:
    ‘At the family court, Mrs Justice Theis said there had been only one other case in the last 30 years of such severe rickets in so young a baby. “This case has demonstrated the difficulties in identifying rickets just by images. In this case it was queried by the radiologist at UCLH [University College of London Hospital], missed by the radiologists at GOSH [Great Ormond Street Children’s Hospital, the UK’s leading children’s hospital] and picked up by the paediatric pathologist,” she said in her written judgment.’

    And for your interest here’s a peer reviewed article in a journal suggesting vitamin D deficiency is nonetheless a cause of childhood rickets.

    J Fam Health Care. 2011 Mar-Apr;21(2):25-9.
    Rickets: concerns over the worldwide increase.
    Lowon J. of Royal Manchester Children’s Hospital.

    “In January 2011 the [UK] government’s chief medical officer Dame Sally Davies recommended all children aged six months to five should be given vitamin D supplements, particularly during winter months when natural sunshine is limited.”
    “Parents and health professionals alike were shocked when it was revealed that a school girl living on the Isle of Wight developed rickets precisely because of her mother’s vigilance at following sun safety rules. NICE, in their latest report (Jan 2011) stated that: “Exposure to the sun has a number of benefits. For example, it increases people’s sense of wellbeing, allows them to synthesise vitamin D and provides opportunities for physical activity”.”

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