Module 3 Flashcards
What does a demographic transition involve?
The movement of all human populations form experiencing high death and birth rates to experiencing very much lower death and birth rates.
What are the steps in demographic transition?
Population increases in size
Move from being predominantly rural to being predominantly urban
Move from having young age structures to having old age structures.
Characteristics of a pre-transitional society
Young
Predominantly rural
Most people were engaged in farming
Few people received much formal education
Fairly distinct gender roles
Autocratic in nature
Definition of epidemiologic (or mortality transition)
The process whereby the prevalence, incidence, and mortality rates of infectious diseases decrease and the prevalence, incidence, and mortality rates of chronic noninfectious diseases increase in countries experiencing economic development. Lead to an overall decline in the crude all cause mortality rate.
When in the demographic transition does the epidemiologic transition occur?
In stage two, when infectious diseases decline.
What occurs after the epidemiologic transition?
The fertility transition
Stage 1`
Represents the time before the demographic change occurs.
Characteristics of stage 1- disease pattern
Disease pattern: age of pestilence and famine
High incidence and mortality rates of infectious diseases
What do demographers call stage 1?
The age of primitive stability
Formerly common and potentially fatal infectious diseases.
Tuberculosis
Pneumonia and influenza
Diphtheria
Whooping Cough
Measles
Polio
Tetanus
Cholera
Smallpox
Typhoid fever
Malaria
Characteristics of stage 1- mortality
High mortality rates
Wide swings in the mortality rate
High infant, child, and maternal mortality
High rate of malnutrition
Low life expectancy
Characteristics of stage 1- fertility
High fertility
Characteristics of stage 1- population
Primitive stability
Little population growth
Very young population
Mainly rural
Characteristics of stage 2- disease pattern
Age of receding epidemics
Both incidence and mortality rates of infectious diseases decline
Epidemics become less frequent
Slow rise in degenerative diseases
Characteristics of stage 2- mortality
Life expectancy increases
Infant, child, and maternal mortality decline
Characteristics of stage 2- fertility
Fertility rates remain high
Characteristics of stage 2-population
Population size explodes
Young population
What caused the decline in infectious disease mortality?
The industrial revolution in the late 19th and early 20th centuries raised the living standards of most people with improvements in:
-Nutrition
-Housing conditions
-Sanitation
-Water supply
The rise in living conditions was then followed by another change in the mid-20th century:
-Abx
-Immunization programs
What also occurred in the 18th-19th centuries that also caused an epidemiologic transition?
Systems of administration, transport, and trade led to a decrease in famine.
Quarantining of ships to prevent disease spread
Smallpox vaccination
Rising living standards
Nutritional improvements
Cleaner water supplies
Sanitation system
Discovery of germ theory of disease
Use of antiseptic procedures in hospitals
Discovery of the role of mosquitos in malaria transmission
Establishment of health departments
Causes of the epidemiologic transition: developing countries in the 20th century
Abx
DDT to control mosquitos
Vaccination against childhood diseases
Oral rehydration
Improved latrines
Rise of the WHO
Improvements in water and sewage
Rising living standards
Mass education
Secularization of attitudes toward health and medicine
Why do fertility rates change in stage 3?
Consequence of the epidemiologic transition. After death rates go down, people start to have fewer children, since nearly all will survive to grow up, but not all can be easily supported.
Characteristics of stage 3- disease pattern
Age of man-made and degenerative diseases
Causes of death are increasingly chronic, non-infectious, and non-communicable
Characteristics of stage 3- mortality
Mortality rates are lower, but continue to decline
Characteristics of stage 3- fertility
Birth rates start to decline
Characteristics of stage 3- population
Expansion of population continues but at a slower rate
Starts to get older
Characteristics of stage 4- disease pattern
Era of delayed degenerative diseases
Low incidence and mortality rates of infectious diseases
Death from chronic, non-communicable diseases
Characteristics of stage 4-mortality
Very low mortality rates
Very high life expectancy
Characteristics of stage 4-fertility
Low birth rates
Characteristics of stage 4-population
Modern stability
Little population growth
Aging population
What is a consequence of the fertility transition?
Populations become older.
Fewer young people are born.
Lower mortality and longer life expectancy also contribute to population aging but not as much as low fertility
Far reaching consequences of chronic, non-infectious, non-communicable diseases being very prevalent
Chronic non-communicable conditions can lead to severe or immediate disabilities:
-Hip fx
-Stroke
And/or slow progressive disability:
-Arthritis
-DM
What is globalization?
Changes in the nature of human interaction across a wide range of spheres, including the economic, political, social, technological and environmental, in which boundaries of various kinds are being eroded.
Emerging infectious dzs
HIV/AIDS
SARS
Ebola
Sin nombre hantavirus
Lassa fever
Legionnaire’s dz
Mad cow dz
COVID-19
Re-emerging infectious dzs
Avian influenza
TB
West Nile virus
Dengue fever
Malaria
MRS
E. coli
Cholera
Drug-resistant gonorrhea
Reasons for emerging and re-emerging infectious dzs
Microbial adaptation and change
Human susceptibility to infection
Poverty and social inequality
International travel and commerce
Bioterrorism-related dzs
Changing ecosystems caused by:
-Climate change
-Deforestation
-Population growth
-The disruption of habitats containing new viruses
Examples of abx resistance
MRSA
Re-emergence of TB due to development of strains resistant to abx
Infectious dzs the homeless are more likely to get
20-40 x the prevalence of TB compared to the gen pop
HIV
MRSA
Hep C
Hep B
Scabies
Body lice
Category A bioterrorism agents
Anthrax
Botulism
Plague
Smallpox
Tularemia
Viral hemorrhagic fevers
Climate-sensitive dzs
Vector-borne dzs
Food or water-borne dzs
Dengue fever etiology
A. aegypti and A. albopictus mosquitos
How higher temp affects dengue fever
-Increased rate of pathogen development of virus replication
-Increased rate of larval development of vector
-Increased biting rate
How changes in rainfall affect dengue fever?
-Vector habitat
-Standing water
How higher humidity affects dengue fever
It’s necessary for mosquito survival
Why are there more biting opportunities for dengue fever?
The mosquito is well-adapted to the urban environment, and there is a high population density.
Challenges of the future
-Rapid pop aging will occur throughout most of the world
-Declining pop size will occur in some countries without immigration, due to very low fertility
-Exploding pop size will occur in other countries with the rapid urbanization that goes with it, because they are in earlier stages of the demographic transition.
-Increasing pop size overall
-New emerging and old re-emerging infectious dzs are appearing around the world
-We may see declining life expectancy in some countries due to non-communicable dzs and conditions
-The effects of climate change will be wide-ranging
