Epidemiological Transition: Concept, Characteristics And Examples

The epidemiological transition is defined as the set of long-term changes that occurs in the health and disease patterns of human populations, as well as in the interactions between these patterns and their causes and consequences in economic, demographic and sociological terms.

The epidemiological transition theory was formulated for the first time in 1971, in an article published by the Egyptian-American epidemiologist Abdel Omran. In this publication Omran proposed an integrative model for epidemiology in relation to demographic changes in human populations.

Through the years, several authors have made significant contributions to this theory, in order to facilitate the description and / or understanding of the changes related, not only with the health and disease patterns of nations, but also with the transformation health services based on these changes.

Article index

  • one

    Why speak of epidemiological transition?

  • two

    The first transitions of humanity

  • 3

    Characteristics of the epidemiological transition

    • 3.1

      Other models different from the “classic”

  • 4

    Epidemiological transition in Mexico

  • 5

    Epidemiological transition in Colombia

  • 6

    Epidemiological transition in Spain

  • 7

    Epidemiological transition in Argentina

  • 8

    References

Why speak of epidemiological transition?

The theory of epidemiological transition was born as a way to explain the relationship that exists between health and disease patterns of human populations and demographic, social, economic and even political and cultural dynamics.

In slightly simpler words, this theory explains how the health / illness of the members of a population is related to the socioeconomic and demographic conditions inherent to it.

It also explains how they change over time as a function of the other, either to the benefit or the detriment of the population, that is, towards an increase in mortality or life expectancy.

The first transitions of humanity

In human history, man began to experience the first epidemiological transitions when nomadic communities began to settle and organize into more complex civilizations and societies.

The first human settlements suffered from different diseases derived from the sudden closeness to the animals that they used to transport and / or feed themselves (zoonoses).

Later, the advent of trade and exchange of items between neighboring populations contributed to the spread of other diseases of different origins (viral, bacterial, parasitic).

Other diseases later affected civilizations as men began to explore and discover new environments, and with subsequent globalization many regional evils became global.

Characteristics of the

epidemiological transition

According to Omran’s original publication in 1971, the epidemiological transition of a nation is directly related to its social and economic development.

This author divides the process “classically” (for Western countries) into four successive stages, phases or eras, which have probably elapsed over the last 200 years:

  1. High mortality: due to the negative effects of overcrowding and malnutrition or malnutrition; to different contagious diseases and perinatal problems, that is, during gestation (pregnancy), during childbirth or in times very close to delivery.
  2. Decrease in mortality, infectious diseases and pandemics: which means an increase in the life expectancy of the population, as well as in fertility and health care systems.
  3. Development of chronic and degenerative diseases: mainly caused by man and his lifestyle, meaning food, behavior, social relationships, addictions, among others.
  4. Decrease in chronic pathologies and increase in others: this fourth phase has to do with the decrease in chronic and degenerative pathologies, but with the increase in mortality rates caused by other “social” pathologies such as accidents and deaths due to causes related to the violence.

It is important to establish the following:

Epidemiological transitions in a nation are not necessarily irreversible, as it is also true that a nation may present social groups with different epidemiological profiles, closely related to existing socioeconomic and demographic differences, which makes the health / disease pattern different. depending on where it is studied and on what scale.

Other models different from the “classic”

Omran also established two other “models”:

The accelerated model : experienced by the Eastern European regions, the countries of the former Soviet Union and Japan. It is accelerated because it occurred in the last 50 years.

The delayed or late model : that characterizes the “third world” countries, where there are still high birth rates (in most) and where mortality decreased with the advent of new health technologies and greater government attention, especially after the Second World War.

Epidemiological transition in Mexico

Mexico City

Mexico, as a Latin American country, is framed in a “late” or “intermediate” epidemiological transition model in relation to Europe and other developed countries, since the progression of said transition occurred especially after the Second World War, as it happened with many other countries in the region and it does not seem to have come to an end.

Between the 20th century and the 21st century, mortality rates in this country decreased and, consequently, life expectancy increased from 36 years (in the first two decades) to 75 years (during the first decade of the 21st century).

By 1950, mortality in Mexico was closely related to various infectious diseases, while closer to the 21st century, by the 90s, there was an increase in deaths from chronic degenerative diseases and different kinds of accidents.

This “positive” transition was the result of:

  • Campaigns to prevent the transmission of communicable diseases.
  • Control and eradication of certain diseases.
  • Increased quality of life.
  • Improvement of cultural, economic and social conditions.

Although this was true for a significant part of the Mexican population, both at that time and today, there are groups and communities where poor sanitary conditions, poverty and lack of health education still prevail, which is why infectious diseases of different types persist.

Epidemiological transition in Colombia

Bogota

Colombia has a very similar situation to that of Mexico, which authors such as Marinho et al. Describe as a “recent” (late) transition, the same as that which has occurred in many countries in the region such as Brazil, Costa Rica and Venezuela, characterized by the recent emergence of chronic diseases and the decline in infectious diseases.

However, for other authors such as Gómez (2001), this country conforms to an intermediate transition model, with mortality and fertility patterns between the “fast” and “slow” models.

However, in this country there are still problems of poor nutrition and many neglected communicable diseases, but at the same time there is a rapid expansion of chronic and other emerging diseases.

Epidemiological transition in Spain

Madrid

In Spain, as well as in much of the European continent, the epidemiological transition is said to have followed the “classical” model and concluded around the 1950s, at which point the high infant mortality rates due to infectious diseases.

In a study carried out in 1996, published by Pompeu and Bernabeu-Mestre, a 70% reduction in adult mortality was described between the period 1900-1990, a case similar to the decrease in infant mortality of 204 deaths per 1,000 live births in the early 1900s, to 7 per 1,000 live births in the late 1990s.

During this period of time, however, there were two events that had great significance in relation to the transitory increase in mortality rates: the Spanish flu epidemic, in 1918, and the civil war, between 1936 and 1942.

Life expectancy in this country went from 35 in 1900 to 77 years in 1990, which translates into a “gain” of more than 40 years, an increase of more than 100%.

Likewise, other causes of death such as infectious and non-infectious diseases were very influential during the first decades of the twentieth century, increasing the number of deaths from non-infectious diseases by half of the century and decreasing deaths from infectious diseases by 95% for the 1990s.

The epidemiological transition in Spain was accompanied, as in most of Europe, by a progressive improvement in health care, hand in hand with an increase in the number of registered health professionals, number of hospital beds and budget allocated to health .

Other improvements included those related to access to potable water and to piped and toilet systems that occurred between 1960 and 1970:

  • By 1950 more than 60% of the homes in this country did not have running water, but this decreased by 98% by 1991.
  • Likewise, 48% of the dwellings lacked toilets and by the end of 1990 this number dropped to 3%.

Epidemiological transition in Argentina

Buenos Aires

Curto et al., In their 2001 publication, carried out an analysis of the epidemiological transition in Argentina, dividing the causes of death into four groups:

  • For infectious and parasitic diseases: where yellow fever, cholera, smallpox, etc. are included.
  • For chronic and degenerative diseases: where, among others, diabetes and cirrhosis are grouped.
  • Due to deficiency diseases: caused by nutritional deficiencies and others.
  • For sociopathogenic diseases: including psychiatric and other “external” causes.

Through the analysis of demographic data corresponding to several years and historical records up to the date of publication, this group of researchers sought to determine which model of epidemiological transition the country conformed to (in accordance with the three approaches proposed by Omran in 1971). .

In their results they state that they do not have enough records to determine phase 1 of the epidemiological transition, that is, they do not have information regarding the causes of death and other demographic parameters of the 19th century.

They establish that Argentina was around 40 years in “phase 2”, where mortality relative to chronic and degenerative diseases increased to 50% among all causes of death between 1916 and 1950, at the same time when deaths from infectious diseases and parasitic ones corresponded to 8%.

The decrease in pandemics during this phase was possible thanks to the consolidation of public health models that included vaccination, social security, welfare and social security.

They delineate a “phase 3” of more than 30 years starting in 1956, where chronic diseases accounted for about 80% of all causes of death by 1982 and the percentage of deaths from infectious and parasitic diseases remains relatively constant at a 10%.

They associate this persistence of deaths from chronic and degenerative diseases due to an increase in life expectancy and the prevalence of smoking and sedentary lifestyle as risk factors for different chronic conditions.

In the period between 1982 and 1999 (phase 4) the percentage of deaths due to chronic and degenerative diseases decreased to 72%, but the percentage of deaths due to diseases or socio-pathogenic conditions increased from 4 (in 1916¨) to 7.5.

Sociopathogenic diseases include suicides, deterioration of the quality of life due to stress and overcrowding, accidental deaths, homicides, etc.

Based on these results, the authors propose that Argentina had an epidemiological transition very similar to that of the classical western model proposed by Omran, but that it may present considerable differences when evaluated with respect to individual provinces and communities.

References

  1. Barrett, R., Kuzawa, CW, McDade, T., & Armelagos, GJ (1998). Emerging and re-emerging infectious diseases: the third epidemiologic transition. Annual review of anthropology, 27 (1), 247-271.
  2. Bolaños, MGV (1999). The theory of epidemiological transition. The Colegio Mexiquense.
  3. Curto, SI, Verhasselt, Y., & Boffi, R. (2001). The epidemiological transition in Argentina. Scientific Contributions, 13, 239-248.
  4. Escobedo De Luna, JM Epidemiological transition in Mexico and the evolution of its mortality. Accessed on, 27, 43-49.
  5. Frenk, J., Frejka, T., Bobadilla, JL, Stern, C., Lozano, R., Sepúlveda, J., & José, M. (1991). The epidemiological transition in Latin America. Bulletin of the Pan American Sanitary Bureau (PASB); 111 (6), dec. 1991.
  6. Mackenbach, JP (1994). The epidemiologic transition theory. Journal of Epidemiology and Community Health, 48 (4), 329.
  7. Marinho, FM, Soliz, P., Gawryszewski, V., & Gerger, A. (2013). Epidemiological transition in the Americas: changes and inequalities. The Lancet, 381, S89.

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