HLTC05 Lecture 2: Lec 2 Helman notes
Epidemiology is the study of the distribution and determinants of various forms of
disease in the human populations.
-Focus on groups of people both healthy a diseased.
- Epidemoligists try to relate its occurrence and distribution ( lung cancer)
-Fcators most examined are age, sex, martial status, occupation, socio-economic
position, diet, environment ( both natural and man made)
-Cultural anthropology is concerned with cultural variables ( such as health-related
beliefs and behaviours
-Epidemiological concepts ( risk factors)
-They use probability -epidemiology
-Epidemiological surveys use 2 approaches
-1) case-control method; examines samples of the population suffering from a
disease and if possible to demonstrate a statistically correlations btw certain
factors and the occurrence of the disease. (history of those smoking and suffering
from lung cancer)
-2)cohort study approach; healthy population (some of whom are associated with
hypothetical risk factors such as smoking) is followed up over time, waiting for a
particular disease to occur.
- “risk factor” has a limited predictive value for ex. Not all heavy smokers will
develop lung cancer, not al immigrants will suffer a suicidal depression and all
TYPE A personalities will develop coronary heart disease.
-Factors affecting individual – genetics, physical, psychological and socio-cultural
-Murphy and Brown- 1980 study of 111 in London; psychological and physical ill
health was proceeded by one or more sever life event (previous 6 months)
-Macro-level ; Black report in 1982 showed how in the UK there is a relationship
btw social class and health
-Low SES---poor ---health high ---mortality rate (health and income)
-Water sanitation, polluted water and poor food supplies and inadquent housing
-Aetiology – study of causes of diseases
-Racial discrimination have risks to ; hypertension, low birth weight, respiratory
illness and mental illnesses
-Trostle; epidemiology is a “culture”
-1)about 10,000 years ago, shift to an epidemiological transition to an
AGRICULTURAL subsistence economy ( shift from foraging to food
-Emergence of infections
-2)About a century ago, second transition; IMPROVED nutrition and medicine
-Decline in infectious disease and a RISE in non-infectious, chronic and
degenerative diseases( man-made disease)- pollution/industrial age
-3) RE-EMERGENCE of infectious diseases and the emergence of novel
(strange/odd) disease. Many of the emerging/re emerging pathogens are antibiotic
resistant and some multi-antibiotics resistant
-INEQUALITY between/within societies, accerlerating the spread of spread
-Human populations are currently experiencing the 3rd
-MACROPARASITISM- the changing pattern of inequality
-Disparities in wealth
-Social stratification evolved because it brought benefits to emerging elites-
resources that improved health
-Parasitism; when organisms use others as a continuing source of food/energy
-1ST- shift from foraging to primary food production
-The domestication of plants and animals in the Neolitic increased infectious
-Increase in population size and density , sedentarism (sitting work), cultivation
(land/crops), and social stratification
-2nd – rise of chronic disease (decline in infectious disease
-3rd- antibiotics losing their affectiveness
-Globalization of re-emergent infectious disease and emergence of novel disease
that threaten human population
-Farmer claims that ‘‘emerging’’ diseases are usually presented as a result of
human behavior or microbial changes.
-‘‘heirloom species’’ as parasites that we share with early hominids’ anthropoid
ancestors and that remained with hominids even after speciation.
-Head and body lice (Pediculus humanus), pinworms, protozoa found in modern
humans and bacteria such as salmonella, typhi and staphylococci (Cockburn,
1967a, b) are examples of heirloom pathogens.
-insect bites, processing and eating contaminated meat, and animal bites are
sources of zoonotic disease.
-women gather and men hunt (the producing segment of society), they are
differentially exposed to disease vectors in the course of their daily subsistence
The first epidemiological transition
-Agriculture in the Old World is evident from about 10,000 years ago.
-Five independent areas of cultivation are found in Mesopotamia, Sub-Saharan
Africa, South- east Asia, northern China and southern China
-development of primary food production is the basis of the changing disease
-increase in population size and density, sedentarism, the domestication of animals,
extensive ecological disruption from cultivation and the rise of social and
economic inequality are all factors that increase infectious disease risk.
-Sedentarism increased parasitic infection because of proximity of the living areas
to source of waters and the areas where human waste was deposited
-Cultivation often exposes workers to insect bites, and diseases such as scrub
typhus becomes common
-Environmental disturbances during the clearing and cultivating of land increase
human contact with arthropod vectors that prefer human habitats and that carry
yellow fever and filariasis.
-agriculture subsistence increased dietary deficiencies that had health implication
for agricultural- ists after the Neolithic
-Agricultural subsistence invariably reduces the variety of foods that are available
to people (Armelagos, 1987) and many increase a reliance on a single-grain crop
such a millet, rice, wheat or maize.
-urbanization of human populations and expansion into new ecological zones
represents one of the most important forces in the evolution of infectious disease
-In line with his metaphor of macroparasitism, McNeill (1978) describes
civilizations as ‘‘digesting’’ encountered populations, as in the swift decimation of
Native Americans by disease vectors that cleared the path ahead of the explorers
2ND epidemiological transition
-increasing prevalence of chronic diseases is related to increases in lifespan
longevity that have occurred over the past few centuries.
-development of the germ theory of disease has been considered as the major force
behind the decline of some infectious diseases.
-The development of immunization resulted in the control of many infections and
was the primary factor in the recent eradication of smallpox; as well, in developed