The origins of human disease: a short story on "where diseases come from"

The rise and fall of diseases: reflections on the history of population health in Europe since ca. 1700

This essay explores the amazing phenomenon that in Europe since ca. 1700 most diseases have shown a pattern of 'rise-and-fall'. It argues that the rise of so many diseases indicates that their ultimate cause is not to be sought within the body, but in the interaction between humans and their environment. In their tireless pursuit of a better life, Europeans have constantly engaged in new activities which exposed them to new health risks, at a pace that evolution could not keep up with. Fortunately, most diseases have also declined again, mainly as a result of human interventions, in the form of public health interventions or improvements in medical care. The virtually continuous succession of diseases starting to fall in the 18th, 19th and 20th centuries suggests that the concept of an “epidemiological transition” has limited usefulness.

Application of Disease Etiology and Natural History to Prevention in Primary Health Care: A Discourse

The principles of etiology and natural history of disease are essential to recognizing opportunities for prevention across the illness spectrum. They have a bearing on how illness is experienced, how differently it can be perceived at the time of first contact with the health system, and how it may appear at later stages. Opportunities for prevention arise at every stage in the process, and three main levels are described: primary, secondary, and tertiary. Prevention strategies include health promotion focused on determinants, clinical prevention to reduce modifiable risk factors, case finding, screening, and addressing functional outcomes relevant to quality of life; the importance of preventing errors is also recognized. The distinction between incidence effects and treatment effects of prevention is explored. This review also examines the differing roles of language in health science and public communication, aspects of disease classification, related issues in patient-centered care, the prevention paradox, and integrated models of disease prevention.

What determines age-related disease: do we know all the right questions?

The average human lifespan has increased throughout the last century due to the mitigation of many infectious diseases. More people now die of age-related diseases than ever before, but these diseases have been resistant to elimination. Progress has been made in treatments and preventative measures to delay the onsets of these diseases, but most cancers and vascular diseases are still with us and they kill about the same fraction of the population year after year. For example, US Caucasian female deaths from breast plus genital cancers have remained a fairly constant approximately 7% of the age-related disease deaths from 1938 to 1998 and have been consistently approximately 2-fold greater than female colon plus rectal cancer deaths over that span. This type of stability pattern pervades the age-related diseases and suggests that intrinsic properties within populations determine these fractions. Recognizing this pattern and deciphering its origin will be necessary for the complete understanding of these major causes of death. It would appear that more than the random processes of aging drive this effect. The question is how to meaningfully approach this problem. This commentary discusses the epidemiological and aging perspectives and their current limitations in providing an explanation. The age of bioinformatics offers hope, but only if creative systems approaches are forthcoming.

On the relationship between individual and population health

The relationship between individual and population health is partially built on the broad dichotomization of medicine into clinical medicine and public health. Potential drawbacks of current views include seeing both individual and population health as absolute and independent concepts. I will argue that the relationship between individual and population health is largely relative and dynamic. Their interrelated dynamism derives from a causally defined life course perspective on health determination starting from an individual's conception through growth, development and participation in the collective till death, all seen within the context of an adaptive society. Indeed, it will become clear that neither individual nor population health is identifiable or even definable without informative contextualization within the other. For instance, a person's health cannot be seen in isolation but must be placed in the rich contextual web such as the socioeconomic circumstances and other health determinants of where they were conceived, born, bred, and how they shaped and were shaped by their environment and communities, especially given the prevailing population health exposures over their lifetime. We cannot discuss the "what" and "how much" of individual and population health until we know the cumulative trajectories of both, using appropriate causal language.