the branch of medical science conerned with the incidence, distribution, and control of diseases that are prevalent among a population at a special time and are produced by some special causes not generally present in the affected locality
Stage 1: Pestilence and Famine
-high CDR -Malthus calls these deaths "natural checks"
What were the main causes of human deaths in stage 1?
infectious diseases, parasitc diseases, and accidents and attacks from animals and other humans
What was history's most violent stage 1 epidemic?
the Black Plague
How many people died from the Black Plague?
25 million Europeans and 13 million Chinese
Stage 2: Receding Pandemics
rapidly declining CDR
What reduced the spread of infectious diseases?
-improved sanitation, nutrition, and medicine
What disease caused an epidemic during the Industrial Revolution?
What eradicated cholera?
the construction of water and sewer systems
In what areas did cholera persist and why?
developing regions (sub-Saharan Africa, South Asia, Southeast Asia, Hispaniola etc.); people lacked access to clean drinking water
What system helped to explain and battle stage 2 pandemics?
Geographic Information System (GIS)
Why were the poor more likely to be affected by cholera?
they were more likely to use contaminated water
Stage 3: Degenerative Diseases
moderately declining CDR
How is stage 3 characterized?
a decrease in deaths from infectious disases and an increase in chronic disorders associated with aging (cardiovascular diseases, cancer, etc.)
Why do sub-Saharan Africa and South Asia have the lowest incidence of cancer?
they have a low life expectancy
Stage 4: Delayed Degernative Diseases
low but increasing CDR
How is stage 4 characterized?
the major degenerative causes of death linger, but the life expectancy of older people is extended through medical advances, as well as better diets and excerise; bad diets result in obesity
Possible Stage 5: Infectious Diseases
a reemergence of infectious and parasitic diseases, resulting in a high CDR
What are the 3 reasons for stage 5?
evolution, poverty, and increased connections
-infectious diseases are evolving and adapting to drugs and insecticides -antibiotics and genetic engineering add to the emergence of new strains of viruses and bacteria
How was malaria first eradicated? Why is it back?
DDT was sprayed in areas infested with mosquitos; the evolution of DDT-resistant mosquitoes
-poorer areas have unsanitary conditions -people can't afford drugs for treatment
Why is tuberculosis still prevalent in poor areas?
patients are too poor to continue with the treatment, and stop taking the drugs
Reason: Increased Connections
-new pandemics are emerging because of relocation diffusion -motor vehicles, airplanes, etc. allow people to travel around much faster, able to spread a disease quicker
What are some of the most lethal pandemics?
AIDS and HIV
Why did the number of cases of AIDS rapidly drop?
the expansion diffusion of medicines like AZT
infant mortality rate (IMR)
the annual number of deaths of infants under one year of age, compared with the total live births
What do low IMRs show about a country?
a good healthcare system; well-trained doctors and nurses, modern hospitals, and large supplies of medicine
What is the IMR in developed countries?
What is the IMR in sub-Saharan Africa?
the average number of years a newborn infant can expect to live at current mortality levels
Where is life expectancy high? What is it?
wealthy countries in Europe; 80
Where is life expectancy low? What is it?
poor countries of sub-Saharan Africa; 60
What do developed countries offer to people who are unable to work?
public assistance and healthcare
How much do government programs pay for healthcare costs? Individuals? (in developed countries)
more than 70%; less than 30% EXCEPTION: the US (individuals pay over 55%, similar to developing countries)
What are things that do NOT indicate overpopulation?
density, size, clustering in of a population
What is overpopultion indicated by?
the relationship between population and a region's level of resources
What is happening in overpopulated sub-Saharan Africa?
-inability of the land to sustain life -land declines in quality, causing more effort to be needed to yield the same amount of crops (extending the working day) -women have more children for help with work