Join or Renew and Choose Your Gift
- Offer ends Dec. 17
- Discounts on travel and everyday savings
- Subscription to AARP The Magazine
- Free membership for your spouse or partner
Epidemiology is the study of the distribution and determinants of health-related states or events. It has traditionally been associated with the study of external agents of disease (microbial infectious agents). Events such as the Black Death, which killed about one-third of the population of Europe during the Middle Ages, have left their trace in the collective unconscious and are still largely perceived as being caused by external environmental agents. Progress in medical science, however, has changed the perceptions of epidemiology as new patterns of illness and disease are confronted.
The first transition in epidemiology occurred over a period of about one hundred years during the nineteenth and twentieth centuries, when humankind progressively curbed the major epidemics of infectious diseases. Some, such as smallpox, were completely eradicated, while some, such as measles, diphtheria, and tetanus, have been significantly reduced. Even taking into account the emergence, or reemergence, of diseases like AIDS (acquired immunodeficiency syndrome), Ebola fever, and malaria, infectious diseases, in many parts of the world, are not the immediate universal threat today that they once were.
The reduction of epidemics and infectious diseases has led to a considerable increase in life expectancy. As a result, there has been an increased appearance of manifestations linked to aging (the so-called degenerative, or chronic, diseases, e.g., some cancers, cerebrovascular disease, and certain mental disorders such as Alzheimer's disease). Major changes in behavior and lifestyles have also appeared, albeit more recently, including driving cars, changes in smoking and diet, and an increased pressure related to work or unemployment. These changes have led to new patterns of disease, distinguished by the growth of the "human-made" diseases such as lung cancer, coronary artery disease, and motor-vehicle injury. Many of these diseases, of course, are not new and have complex etiologies, but the shift from the prevalence of infectious diseases to the prevalence of chronic diseases defines this second transition that has occurred in every part of the developed world. In the developing world, this transition is rapidly emerging, putting these countries under a new burden while they are still suffering from the ongoing—and in some cases increasing—onslaught of the acute communicable diseases.
The next transition may be brought about by changes in how individuals relate to disease. Patterns of usage of health services, ranging from the limitation of services on economic grounds to the provision of technologically advanced services such as organ transplantation and in vitro fertilization, are continually shifting. At the same time, efforts made by individuals to manage the consequences of nonfatal impairments and disabilities are also likely to bring changes in the distribution and determinants of health-related states or events. Epidemiologic transitions are, in fact, an ongoing phenomena, with one phase overlapping another. These transitions will continue as the face of disease continues to change.
MICHEL C. THURIAUX
Author Info: MICHEL C. THURIAUX, The Gale Group Inc., Macmillan Reference USA, New York, Gale Encyclopedia of Public Health, 2002
Enter your symptoms in our Symptom Checker to find out possible causes of your symptoms. Go.
Enter any list of prescription drugs and see how they interact with each other and with other substances. Go.
Enter its color and shape information, and this tool helps you identify it. Go.
Find information on drug interactions, side effects, and more. Go.
From companies that meet the high standards of service and quality set by AARP.
Members save on purchases from The Popcorn Factory®.
Members save from top retailers online at Everyday Savings Center powered by NextJump.
Members save 10% on all Amazon Kindle e-readers and the Kindle Fire HD tablet.
Get the most out of your AARP membership – opt-in to receive AARP emails today!
Register at a location near you to keep your driving skills sharp.
Find opportunities to volunteer in your neighborhood.
NASCAR champ Jeff Gordon teams up with AARP's Foundation.
AARP Foundation Prepaid MasterCard brought to you by Green Dot.
Nothing has been viewed