Disease and economic development 11.2 Flashcards
What does the epidemiological transition model describe?
The relationship between development and changing patterns of population age distribution, mortality, fertility, life expectancy and causes of death.
Changes are driven by improvements in health care, standards of living and the quality of the environment
What are the three epidemiological phases?
The age of pestilence and famine
The age of receding pandemics
Post-industrial societies-mortality slackens
Some people suggest a forth phases- the age of delayed degenerative diseases
Describe the first phase of the epidemiological transition
In pre-industrial societies mortality is high and fluctuates from year to year. Life expectancy is low and variable, averaging around 30 years. Poor sanitation contaminated drinking water and low standards of living make people more susceptible to infectious diseases which dominate mortality. Population growth is slow and intermittent. Today all countries have passed through this phase
Describe the second phase of the epidemiological transition
The age of receding pandemics. In industrial societies with advances in medical technology, diet and hygiene, and improvements in living standards, epidemics, causing large-scale mortality become rare. Life expectancy rises above 50 years and population growth is sustained. There is a shift of main cause of death from infectious diseases to chronic and degenerative diseases. This phase includes many LIDCs today
Describe the third phase of the epidemiological transition
Further improvements in medical technology, hygiene and living standards mean that mortality related to infectious disease is rare. Degenerative diseases becomes the main cause of mortality. Man-made diseases becomes associated with environmental change (e.g. cancer) become more common. Many emerging economies economies such as Brazil and China are in this phase
Describe the fourth phase of the epidemiological transition
The age of delayed degenerative diseases - where medical advances delay the onset of degenerative CVD. The so-called cardiovascular revolution of the past 40 years has raised average life expectancy in ACs from the early seventies to the mid-eighties. Obesity and diabetes become increasingly common and problematic health factors
Why have communicable diseases largely been eliminated in ACs?
Advancements in medical diagnoses and treatments, high standards of living, proper sanitation, clean water supplies and appropriate food intake.
Why are degenerative diseases more prevalent in ACs?
Prolonged life expectancy inevitably increases deaths to degenerative diseases.
In ACs, overnutrition and excessive consumption of sugar, carbohydrates, fats and salts are increasing health risks and the prevalence of non-communicable diseases such as CVD, type-2 diabetes and several types of cancer
These heightened risks, are increasingly apparent in younger age groups
What is the prevalence of Cancer like in ACs vs LIDCs?
Cancer is often regarded as a disease of high-income countries yeat 70% of all cancer deaths are in low-middle income countries.
The incidence of cancer in poorer countries is rising and expected to double by 2023.
However if we ignore absolute numbers, the incidence of cancer standardised by age structure remains much greater in ACs than in LIDCs and EDCs
What three groups are communicable diseases classified into?
Animal-borne e.g.vector
Water-borne e.g malaria
Food-borne e.g. undernutrition
What factors mean that communicable diseases dominate mortality in LIDCs?
Related to poverty, failure to control communicable disease reflects inadequate health care services and lack of resources to tackle to cause of disease.
Other factors include inadequate nutrition, poor environmental and living conditions and geography
How does inadequate food intake affect disease
Gives rise to undernutrition and malnutrition. Both are widespread in the poorest countires.
Health and diet are closely linked. Undernutrition and malnutrition weaken the immune system and increase the risks of bacterial and viral infections.
Malnutrition caused by protein deficiency is responsible for non-communicable diseases such as marasmus. Diseases caused by lack of vitamins include rickets (vitamin D)
How does poor environmental conditions spread communicable diseases?
Water pollution is mainly caused by a lack of proper sanitation and hygiene. Polluted water provides a reservoir for cholera, typhoid etc.
Poor drainage provides breeding sites for disease vectors such as mosquitoes.
The threat of infectious diseases is increased in LIDCs by the appalling conditions in which millions of people live. Slum housing and overcrowding are closely linked to TB and other respiratory diseases
How does geography influence communicable diseases in LIDCs?
Most of the world’s poorest countires are in the tropics and sub-tropics. High temperatures and abundant rainfall create the epidemiology for a wide range of infectious diseases-malaria, dengue fever and sleeping sickness, which are absent in cooler climates of higher latitudes.
