A luncheon Session is scheduled for the 80th annual meeting of the American Association for the History of Medicine, to be held in Montreal, Canada, 3-6 May 2007.
HISTORY IN THE POST-GENOMICS ERA: NEW PERSPECTIVES ON HEALTH, DISEASE, AND MEDICINE
Chair: Guenter B. Risse
Abstract
Our health-conscious culture is increasingly obsessed with the dangers posed by a number of diseases. AIDS, cancer, flu, malaria, tuberculosis and SARS are portrayed as global menaces. Global warming and industrial pollution are viewed as threats to our environment. Bioterrorism also looms darkly. The recent mood is plainly apocalyptic, in sharp contrast with the stance dominant after World War II, when the end of infectious disease was heralded. Scientists, from historical ecologists and medical geologists to evolutionary and molecular biologists, all are actively studying the complex web of relationships between nature and human culture. Their results, to date, have already led new and often revolutionary insights into present and past events. Questions are raised about the fluctuating ecosystems and their impact on human health and disease. Should medical historians take advantage of this growing body of knowledge and include it into their future interpretations?
The history of health and disease has a rich tradition extending back to the Hippocratic treatise Airs, Waters and Places, the first text expressing ecological notions about the interplay between the environment and humans responsible for disease. As early as 1933, Henry Sigerist and later Owsei Temkin insisted that the history of disease was the starting point of all medico-historical investigations. However, the subject matter has remained somewhat peripheral from the traditional tasks of medical historians, namely to search and analyze the writings and practices of the medical profession and place them within their socio cultural contexts. Most so-called “grand narratives” describe the presence of prominent epidemics and particular diseases in the context of medical discovery and heroic actions in battling such ailments. Even Roy Porter’s recent The Greatest Benefit to Mankind failed to integrate disease into the main body of his book, reserving a few pages to “plagues and people” under the rubric “roots of medicine.”
Sweeping narratives are no longer fashionable in medical history, discarded for more focused and detailed studies and reconstructions that wish to expose the shifting, complex and contingent nature of medical ideas, practices, and values. Historians are reluctant to employ modern scientific insights when studying past diseases. Since the 1970s, such endeavors are often disparaged as ”present-centered” and labeled “tunnel history”. Social constructionists complain about “the enormous condescension of posterity,” distorting the true past through the employment of alien perceptual and conceptual categories. In fact, authors are urged to engage their subjects and sources “naturally,” on their own terms. This call has found resonance among a new generation of academics broadly interested in social studies concerning health-related issues and practices. These scholars insist that disease is just another social construction with multiple labels. Some even question whether a scientific identification of a particular disease has any historical value. Should we simply, then, study the impact of human disability on culture and society and concentrate on the changing ideas as well as efforts to cope with them?
The field of medical history is steadily expanding. Today, historians employ a number of lenses to understand humanity’s multidimensional character. Like Sigerist and Temkin, I would argue that all medico-historical subjects should only be properly understood within the context of prevailing health conditions. This is particularly crucial for a spectrum of activities broadly labeled as public health. Moreover, there is an urgent need to integrate biological and social contexts. A balanced biological-cultural approach examines health and disease as representations of biological reality, culture-specific constructions, and politically shaped phenomena. Society and culture are critical in shaping prevailing health conditions.
An ideal history of health and disease therefore, should simultaneously take into account shifting ecologies and changing social realities. The “framing” metaphor allows for parallel studies and promises a better juxtaposition of the material and cultural world. An excellent example is the historical study of the human body. Framed as a biological reality, its anatomy and functions are objects of scientific investigations. As a migrating species, we seek our own “optimum living range” within particular landscapes and climates. Here humans are exposed to a range of plant and animal life essential for shelter and nutrition while the inevitable exposure to microbial parasites and pathogens can result in disability and death. To assess the evolution of past ecologies of health and disease and make sense of the production of medical knowledge, current biomedical information employing genetic, pathological and epidemiological criteria is essential.
Physicians, epidemiologists, and qualified realist historians have traditionally engaged in historical investigations. This science-inspired sleuthing was based on fragmentary past descriptions, clinical hunches, dubious statistics, and isolated pathological specimens that often yielded questionable retrospective diagnoses of past diseases. Vigorously challenged by their peers, ignored by social historians, these isolated discoveries frequently lacked sufficient context and representation. Recently, however, new scientific tools show a far greater promise for enhancing our contemporary and historical knowledge regarding issues of environment, health and disease. Today, sophisticated diagnostic technologies, developed by our burgeoning forensic sciences, include electron microscopy, tissue analysis, and DNA recovery from skeletal and mummified human remains. Techniques such as computerized tomography and magnetic resonance imaging are non-invasive forms of pathological detection. Sophisticated biochemical analyses discover the nature of diets. Ingested foodstuffs can be extremely informative for both historians and medical researchers. They disclose the range of human habitat and activities—witness the extraordinary window into Neolithic life provided by the discovery of the Tyrolean “iceman.”
We live, indeed, in the post-genomics era. The examination of molecular and genetic mechanisms responsible for human evolution and health is in full swing. Ancient DNA is a relatively new field of study but extracting and sequencing it remains both difficult and controversial. Extensive DNA degradation follows death and thus allows extremely low yields. Museum specimens, archeological artifacts and fossils, some thousands of years old, are currently analyzed employing the most advanced techniques. Because of its good vascularization, durability and natural sterility, teeth have become the ideal source of ancient DNA. In fact, molecular traces in dental pulp fail to degrade, allowing for the possibility of diagnosing diseases such as malaria, cholera and plague.
The new field of paleomicrobiology now examines host-pathogen interactions at the cellular and molecular level for modeling the evolution of infectious diseases. Using modern laboratory methods, DNA is separated and subjected to tests for the purpose of identifying the presence of specific microorganisms. According to Richard Pollack. “many molecular biologists are becoming historians. Little by little they start to approach genomes not so much as polymers, but as old manuscripts which document the history of life on our planet.” (Signs of Life: The Language and Meanings of DNA, 1994)
The approach must be broadly interdisciplinary, employing a variety of methods and perspectives. Current relevant areas of research include historical ecology, evolutionary theory, biogeography, epidemiology and demography, paleopathology and molecular biology. Insights into the molecular structure of humans and those microorganisms interacting with them are yielding extraordinary results. In October 2005, a British team from the Sanger Center in Cambridge reported that they had decoded the complete DNA sequence of Yersinia pestis. In the same month, another US team from the Armed Forces Institute of Pathology resurrected the influenza virus responsible for the 1918 pandemic. In their quest to discover the true causes of certain infectious diseases, recent studies based ancient bacterial DNA have identified the microorganisms responsible for a number of important past epidemics. In January 2006, Greek scientists revealed that the probable cause for the ancient plague of Athens in 428 BC was salmonella enterica typhi responsible for typhoid fever. Thanks to other genetic studies by a French team in the last few years, the medieval Black Death and subsequent plague epidemics in Europe can be firmly linked to the presence of Yersinia pestis in victims of the disease.
However, caution must be exercised. Such information should be interpreted in terms of historical contingency and carefully integrated into existing frames of evidence. I fully realize that our current scientific criteria are also socially constructed and changeable. Most of the information about paleo-ecological conditions and the findings based on molecular biology continue to evolve and will be subjected to successive revisions, but so is everything else we study and analyze. Searching for motives and meaning, societies tends to shape and conceptualize health conditions in unique ways. Unduly forcing older terminology and meanings into the strictures of modern but frequently contested biomedical knowledge can be misleading. I am keenly aware of the pitfalls, as evidenced in my treatment of clinical cases at the Edinburgh Infirmary. Given the accelerating rate of new knowledge, today no one pretends to write "definitive" histories of anything. Indeed, most conclusions remain speculative, subject to change as archeology uncovers new artifacts and scientific insights change. In the meantime, however, all this information can stimulate further inquiries and encourage the formulation of new questions.
In conclusion: a new bio-cultural history of health, disease and medicine must combine the latest scientific findings with insights derived from social, political, economic and cultural theories and relationships. While difficult to achieve, this synthesis promises to offer a far more nuanced account and understanding of the complexities of human life and health, as well as explain both the biological and political roots of disease. Instead of sweeping generalizations, the task can be accomplished through the employment of local, specific case studies capable of exposing past webs of causality and explaining the emergence of new health threats. In the end, these scientifically-enriched historical perspectives may also contribute to current efforts aimed at understanding and improving global health.
