Medical Geography Research Paper

1. Traditions of Medical Geography

There are four major foci of medical geography. These are: (a) the analysis of relationships between culture, behavior, population, environment, and disease (usually termed ‘disease ecology’); (b) the identification of spatial patterns of disease, and the explanation of those patterns based upon the social, environmental, and cultural processes that generate those patterns; (c) the analysis of geographical considerations in the planning and administration of health systems; and (d) the consideration of health and disease in the broader contexts of society, political economy, social structure, and patterns of power.

For much of the twentieth century, there was a division between research in the geography of disease and the geography of healthcare (Mayer 1982). The former was concerned with the analysis and understanding of spatial patterns of disease; disease as the result of maladaptive relations between people and the environment; and disease as the result of interrelations

between population, behavior, and environment (Meade 1977). Much of this was based on the work of Jacques May (May 1958), a surgeon turned medical geographer at the American Geographical Society, who wrote extensively about the ecology of disease, and the geography of nutrition. The ecology of disease considers the complex relations between the physical, sociocultural, and biological environments on the one hand, and the resulting patterns of disease on the other. May argued that for disease to occur, there must be a coincidence in time and space of agent and host. This statement reflects the implicit emphasis in early medical geography on the geography of infectious diseases. Agents, in this tradition, are the organisms that cause infectious diseases. Most of these are microorganisms such as viruses, bacteria, protozoa, and helminths (worms), although many helminths are also large enough to be grossly visible. ‘Hosts’ are those organisms that harbor the disease. Most medical geography has been concerned with human hosts, though there is no reason that diseases among nonhuman organisms cannot also be analyzed geographically. Some diseases, such as African Trypanosomiasis (African Sleeping Sickness) and yellow fever involve animal reservoirs, and disease ecologic analyses must therefore consider animal behavioral and spatial patterns.

The other major tradition of medical geographic research has dealt with geographical aspects of healthcare provision. Themes such as geographical aspects of access to healthcare; optimal location of facilities, ambulances, and services; and the regional planning and distribution of health systems have figured prominently in this tradition.

Until recently, the two major traditions of thought in medical geography—the geography of disease and the geography of healthcare—have been considered separately, the two are frequently inseparable and usually have mutual implications for one another. For example, the geographical distribution of disease is a major determinant of demand and need for healthcare, and this should be an important influence on how and where healthcare is provided to populations. Similarly, the geographical distribution of care can exert a strong influence on the changing distribution of disease.

Though the geography of disease has major implications for healthcare provision, the analysis of disease patterns and the underlying explanation of those patterns have scientific importance in itself. Biological and epidemiological characteristics of the population, environmental exposure to both infectious agents and environmental pollutants and toxins, social and economic characteristics of the population, and the genetic predisposition of the population to certain diseases influence the distribution of disease. The role of genetic influences has been increasingly apparent in medicine and medical science, but the health-related social sciences, including medical geography, have tended to minimize the importance of genetic influences. Genetic influences operate at two levels: one is the genetic predisposition to certain diseases, and the other is the genetic determination of disease. To illustrate the former, family history is a major risk factor for diabetes mellitus, coronary artery disease, and many cancers. Genetic influences in this context operate in the context of individual experience—certainly, habits, customs, and behaviors all contribute to these diseases. The genetic determination of some diseases is less complex on a social level. The cause of diseases such as Tay-Sachs Disease, sickle cell anemia, Down’s Syndrome, and others are completely genetic.

2. The Evolution of Medical Geography

Most medical geographers identify Hippocrates as the first known medical geographer. In addition to being a prominent Greek physician, he was also a major thinker in the relationships between the physical environment and health. In his essay, Of Airs, Waters, and Places (Dubos 1965), Hippocrates noted the importance of climate, water, and other physical characteristics as influences on the health conditions of areas. This was a major advance at the time, in terms of an implicit recognition that disease was not due to divine or mystical forces, but rather to various aspects of the physical environment. Malaria, for example, is a ‘vectored disease’—anopheline mosquitoes transmit the parasites responsible for malaria (plasmodia) from person to person. The only way in which malaria can be contracted without the anophelines that are implicated in its transmission is through blood transfusions. Anophelines can only live in certain climatic, hydrologic, and geomorphologic conditions, depending upon the species of anopheline. Thus, certain environments are not conducive to the existence of anophelines. When this is the case, malaria is absent. This physical relationship was a major theme of Hippocratic thought, and attests to the importance of the human–environment relationship as an influence on disease.

Few advances were apparent in medical geography until the latter part of the eighteenth century and the nineteenth century, with the advent of the ‘public health movement’ in Europe and the Americas. It may be incorrect to think of this as a monolithic movement, but the major idea behind it is that a number of thinkers and social activists saw the local environment as a determinant of public health. Much of the attention was somewhat naively devoted to cleanliness and the minimization of filth for aesthetic purposes, but a major portion of this movement sought to improve the health conditions of the population by improving cleanliness, particularly in urban areas. Rodent control, water quality, and air quality were all major issues in the public health movement, and many diseases are associated with an abundance of rodents, poor water quality, and air pollution. The bubonic plague—the Black Death—which exerted a major influence on European history and has been important in other areas of the world, cannot occur in the absence of rats that carry the fleas that transmit the plague bacillus. Many diseases are waterborne, and these waterborne diseases such as cholera and other diarrheal diseases are major sources of illness in developing countries.

Much of the attention given to environmental influences on disease was countered by the discovery that specific microorganisms caused many diseases. This was caused by the development of microscopic techniques, and focussed attention on the microscopic level. The ‘germ theory of disease’ exerted a profound influence on science and medicine that countered the major emphasis of geographic studies on the macrolevel. It was not until the second half of the twentieth century, with the development and emphasis on the field of environmental health in public health, that there was a major refocusing on the larger scale.

Other roots of medical geography in the nineteenth century came from efforts at disease mapping at the global and national scales. Some of this was the result of the need for imperial powers to know what diseases they could expect to encounter in foreign lands. Another impetus was the scientific curiosity of individuals such as August Hirsch, in his Handbook of Historic and Geographical Pathology (Hirsch 1883). This began the tradition of disease mapping which has always been important in medical geography.

The practical utility of disease mapping and medical geography was further realized during World Wars I and II, where again it became important to know what diseases would be encountered by troops who went abroad from their homelands. Disease mapping thus played a role in the wars.

Following World War II, the major emphasis on medical geography was initially on the development of disease ecology, first based largely on the work of May, and subsequently on that of Learmonth (1988) and others who also sought to understand the interplay of biological, cultural, and environmental factors in disease. The mobility of populations also became a theme for investigation. One of the major themes in geographical thought has been the investigation of migration and spatial interaction. Such has also been the case in medical geography. Prothero (1965), for example, investigated the role of migration in malaria transmission. This research was influential in the formation of policy with the World Health Organization (WHO).

The ‘quantitative revolution’ in geography of the 1960s provided an impetus to new techniques of studying disease and healthcare. Some of the earliest research using more sophisticated quantitative techniques were by researchers such as Gerald Pyle (Pyle 1971) who investigated the spatial patterns of cancers, heart disease, and stroke in Chicago. This research was also significant in that it represented some of the earliest research by geographers to relate the spatial patterns of disease at a metropolitan level to urban structure, and to emphasize the geographical patterns of noninfectious diseases.

The quantitative revolution was also significant in that geographers, who were educated in this tradition, and particularly in urban and transportation geography, began to study the geography of healthcare. They also assessed the spatial behavior of those seeking healthcare and geographical access to facilities, and patterns of inequity and inequality based upon statistical studies and large databases. Some of the most significant work came out of the Chicago Regional Hospital Study, co-directed by the geographer Richard Morrill. This large project resulted in numerous publications and a heightened understanding of the role of numerous spatial factors in the structure of urban healthcare systems (Morrill and Earickson 1968). Some of the major findings of this project were that individuals did not always seek the nearest sources of care; that hospitals were not located optimally for the population that they served; and that factors other than geographical accessibility were important in where people got their care. It also resulted in thought about the differences between equality and equity in the geography of healthcare.

Another subject of many studies following the beginning of the quantitative revolution was spatial studies of disease diffusion or spread. Most of this work concerned and continues to concern contagious infectious diseases. One of the earliest was Pyle’s study of the diffusion of cholera in the USA in the nineteenth century (Pyle 1969). This research demonstrated that the spread of cholera, in three separate epidemics in the nineteenth century, reflected the change in regional structure and connectivity. As transportation systems developed and places became better connected from the early to the late nineteenth century, the pattern of spread of cholera changed from a distance-based contagious diffusion pattern to one based more on the settlement hierarchy, and therefore usually termed a ‘hierarchical’ pattern by geographers.

3. Diffusion Studies and Geographical Information Systems (GIS)

3.1 Diffusion Studies

Disease diffusion has been a dominant theme in scientific medical geography. Subsequent to Pyle’s analysis of cholera, the major advances in understanding diffusion have come mainly from the mathematical modeling of contagious disease diffusion. Among the most influential studies have been those by Cliff and others (Cliff et al. 1981) which combined mathematical models with historical analyses of measles in Iceland. Iceland was chosen because it has been, historically, a relatively isolated island community, and the disease dynamics may be studied with less concern from constant introduction of new cases from outside than in virtually any other region of its population and size. Thus, the internal spatial distribution of disease is more easily studied in such an environment. One of the major findings of these models of measles diffusion is that it is possible to predict the location of an epidemic but not its severity, or its severity but not its specific location. One major task for the future is to develop a truly predictive medical geography that can be precise in predicting the time, location, and severity of epidemics. However, this level of prediction remains elusive.

Reflecting the worldwide importance of HIV AIDS, there have been many studies of the geographical patterns and diffusion of this pandemic. Major works have been written on the spread of HIV AIDS, the dynamics of the epidemic, and its regional context at the national and international levels (e.g., Gould 1993, Shannon et al. 1991).

3.2 Geographical Information Systems

As in other areas of geography and public health, the development of geographical information systems (GIS) has proven to be a major innovation in medical geography. It allows the interactive display of many layers of spatial data, so that, for example, knowing the environmental requirements for the survival and propagation of a vector can lead to a precise display of areas where that vector might survive. An overlay with a ‘buffer’ depicting the range of flight for the vector can illustrate graphically the predicted areas to which the vector can fly. This can then be combined with a view of population distribution. Such a depiction may facilitate the specification of where a disease may remain endemic. This does not necessarily represent a fundamental conceptual innovation, but certainly is a technical advance. It gives more precision to the concepts of disease ecology that also deal with the range and habitats of vectors. Predictions of the future distribution of the disease are then possible based upon the predicted changes in population distribution and environmental modification. These techniques have been used to address the predicted changes in the distribution of vectored diseases that might transpire with conditions of global warming and sea level rise. The use of GIS has not been restricted to research by medical geographers per se, but has been responsible in itself for the growing awareness of the importance of geographical patterns of disease generally in public health and medical disciplines.

4. Health and Social Geography

Healthcare provision is one element of social policy, and this observation has been responsible for some writers placing medical geography within the purview of social geography (Kearns). Health is not merely a medical phenomenon, but is partly a product of social and economic conditions. Just as there has been the development of social epidemiology as a field within public health, so too have writers analyzed the relationship between socioeconomic patterns and patterns of healthcare provision. Some of this emphasis came out of the earlier ‘welfare geography,’ whose proponents sought to develop effective indicators of social well being, and then to appreciate the geographical variation and explanation of those. This also parallels the WHO’s definition of health as a positive state, and not just the absence of disease. This reconsideration has itself represented the major impetus between the ‘new public health,’ which seeks to understand the conditions that promote health, and then to implement policies at a variety of scales that will promote positive health.

Some have suggested further that the use of the new ‘social theory’ in geography should extend to medical geography as well. It is difficult to describe the contours of social theory in geography in 2000, but it is clearly something other than classical sociological theory. Rather, it is an amalgam of Marxist, structuralist, and postmodern concepts. There are some major overlaps in this somewhat broad school of thought with the arguments that medical geography is a subset of social geography, but the major concepts that social theory has brought to medical geography go somewhat further than that. Health is a social condition, created by social and economic structures. Moreover, health, in the tradition of social theory, is a culturally and socially defined concept. Thus, the very categories that are used in defining and discussing health and disease are products of society, and what the discussion reflects, more than anything else, are social concepts. The subject of study thus becomes transformed from the geography of health and disease to the social meaning of health and disease. This is why there is resistance among the proponents of this approach to referring to the geography of health and disease as ‘medical geography’—because ‘medical’ implies the ‘medical model’ of disease, diagnosis, and treatment. It is seen as reflecting the dominance and power structure of contemporary medicine, and the biologically oriented concepts of medicine and medically related sciences, rather than the social concepts described above. A balanced discussion of the geography of health and disease must include this approach, yet it is difficult to evaluate the contribution of these concepts beyond the truisms that they reflect. A valid question is has this set of approaches led to a greater understanding of the geography of health and disease? They certainly provide context. Whether they lead to greater understanding, though, of how and why health and disease are distributed as they are remains to be seen.

Studying the social meanings of health and disease can bear a strong relationship with literary analysis, treating discussions of health and disease as ‘discourses’ or texts to be analyzed in the same way as literary texts. This is done in the hope that this will lead to greater understanding of the ‘meaning’ of the language and concepts that are used to discuss health. In the social sciences generally, such an approach is frequently termed ‘discourse analysis.’

An outgrowth of this tradition, and the emphasis on the sense of place and the ‘lived experience’ of place in geography is the recent interest in medical geography on the importance of place for health, disease, and healing. Places with which people can identify have been termed ‘therapeutic landscapes’ (Kearns and Gesler 1998). The human dimensions of place are taken to be important in the process of healing. People are ill, recover, and remain well in specific places that they experience in personal ways. Explorations of the sense of place in medical geography are an important new direction for the field.

5. Political Ecology of Disease

Human modifications of the environment have led to changing patterns of health and disease. The human impact on the landscape is usually the result of broader social and political forces. For example, Fonaroff (1968) demonstrated how changes in Trinidad’s wage economy removed people from cacao cultivation as their major occupations and resulted in increased rates of malaria. This was because people continued to cultivate cacao and other crops in fields at their homes, and did this at dawn and dusk—precisely when anopheline mosquitoes are most likely to take a blood meal. Thus, changes in the overall economy and in patterns of employment essentially caused increases in malaria incidence and prevalence. The same was true in Meade’s study of land use changes in Malaysia (Meade 1976) where she demonstrated that the intensive development of rubber plantations exposed laborers to malaria because of land use changes that resulted in the development of environments favorable to anopheline reproduction at precisely those locations where laborers congregated on rubber plantations. Taking a longer historical view, the same is true of Lyme disease in the northeastern USA (Mayer 2000). Suburbanization has led to the exposure of people to

‘edge environments’ on the urban periphery adjacent to second growth forest. These are areas that deer preferentially settle, and deer are implicated in the transmission of ticks that serve as the vectors for Lyme disease. Thus, people, agents, and insect vectors are brought into contact with one another, as a result of broader population pressures, land use changes, housing developments, and other social factors. Understanding how government power and human action has resulted in changing patterns of disease has suggested that the concepts of political ecology may be applied to understanding disease patterns—they can be the unintended consequences of decisions and plans in a variety of arenas that result in environmental modification (Mayer 1976, Mayer 2000).

6. Geography and Health Systems Planning

One of the applications of medical geography to health services policy is particularly important in centrally planned and financed health systems such as in the UK. Geographical concepts are crucial to the planning, budget allocation, and needs assessment processes in the National Health Service (NHS). For example, the NHS is divided into regions and subregions (districts). Funds are allocated to districts and regions, and plans developed based upon regional needs. These needs are assessed on the basis of health indicators, regional demographics, and past trends in specific areas. Facility construction and location are anticipated well into the future, and hospitals cannot be modified in their scope of services, size, or facilities without formal approval at the national level. Referral patterns from primary care practitioners (GPs—or ‘general practitioners’) are based largely on proximity to hospitals and specialist consultants. Patients are not free to travel long distances to facilities of their own choice under the NHS—rather, regions are allocated to specific facilities that serve those regions. This is very different to the system that has evolved in the USA, in which there is very little regional planning and co-ordination of facilities and services. Though there were mechanisms for regional planning in the past, these programs were virtually eliminated in the early 1980s as the US healthcare system moved to more of a market orientation.

This is not to say that geographical considerations are not used in the delivery of care in the USA. Trauma systems—formal arrangements of hospitals and prehospital care providers for the treatment of serious injuries—are highly regionalized, with formal patient transfer protocols to higher order centers for the most serious injuries. The same is true for burn care, organ transplantation, and certain other services in selected states and metropolitan areas. For the most part, however, hospitals are able to offer whatever services their planners and administrators deem appropriate. The assumption is that the institution (and presumably the public) will benefit if the market can support those services, and if the market cannot support those services, then they will eventually be eliminated. Needs and demand assessment based upon the population geography of hospital service areas is crucial in individual institutional planning. Thus, needs are assessed in the USA by private facilities in much the same way as any business will assess regional demand for goods. A government orientation that is evident in centrally planned and financed systems such as the NHS is thus not evident in the USA, though individual institutions still focus on regional need. It is more marketing, though, than public service planning. The US system is anomalous in a global context, where most countries have some form of nationalized system. Along with these nationalized systems comes the regional planning of facilities and institutional interrelationships.

7. Medical Geography and Indigenous Health Systems

Many societies, and particularly developing countries, have at least two different healthcare systems that are usually not well integrated. The first is Western-style medicine, with its coterie of diagnostic and therapeutic technologies, medications, and vaccinations. The second is a less formal but important system of traditional or ‘indigenous’ medicine and healing (Good 1987). As the name implies, this system is deeply ingrained in the local culture, and is frequently better accepted by the population than is Western medicine, which is frequently imposed on the society from the outside, or from the national healthcare bureaucracy. Traditional healing may involve herbs and herbal medicine, spiritual healing, and even shamanism. One of the major challenges is integrating the two very different systems together. They have different assumptions of the nature of illness and disease, and obviously different practices of healing and diagnosis. Since indigenous medicine is so frequently better accepted by the local population than is Western-style medicine, people may choose preferentially to use traditional healers rather than Western physicians. This makes traditional medicine more accessible to the population because of fewer cultural barriers, and also because there is usually a greater number of traditional healers than physicians in developing countries. This suggests that the geographical accessibility of traditional healers may be greater than that of Western-style medical personnel. However, for many diagnosable conditions, such as infections, surgical conditions, trauma, and other problems, Western medicine has more effective treatments than does traditional medicine. For other conditions, such as stress-related disorders, traditional healers are often effective. Anthropologists have studied the cultural integration and barriers, and geographers have studied the relationship between these two systems. The greater accessibility to the population of traditional healers suggests that a major opportunity to serve the population resides in integrating the two systems, such that people treated with conditions that are most appropriately treated by Western medical personnel can be seen by physicians and auxiliary personnel, whereas those with conditions that are treatable by traditional healers can be seen by those individuals.

This whole approach may be included in the cultural study of healthcare, in which ‘alternative’ or ‘complementary’ medicine become major subjects of study.

Data from developed countries also indicate that the majority of people frequently consult personnel such as chiropractors, massage therapists, and homeopaths who are usually not considered part of the formal or ‘legitimate’ system of healthcare (Gesler 1991).

8. Future Research

Future research in medical geography is difficult to predict. The following areas are likely to be major foci in the next two decades: (a) the development of a predictive medical geography, in which future geographical patterns of disease may be foreseen with reliability; (b) the analysis of health and disease in the contexts of society and social values; (c) the relationships between global change, including global environmental change, such as global warming, and patterns of disease; (d) the political economy of health systems, and the political ecology of disease; (e) the development of new methodologies and the integration of existing methods, such as mathematical medical geography and geographical information systems.

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