1.a. Classification, patterns, and spread of diseases

Question 1

why do patterns of disease exist between different levels of development?

Answer 1

NCDs in ACs:
- limited transfer of infectious due to vaccinations
- behaviour surrounding diets/alcohol/inactivity=personal
- generally better education and hygiene

Infectious in LIDCs:
- poor living conditions and sanitation => more exposed to pathogens and water-borne diseases
- lack of education/contraception/attitudes towards relationships

Both in EDCs:
-most industrialisation => worst air quality

Question 2

infectious

Answer 2

= caused by pathogenic micro-organisms (eg. parasites and bacteria)
- diseases spread directly or indirectly from 1 person to another

Question 3

non-infectious

Answer 3

= not passes from person to person
- long duration and slow progression
- chronic diseases

Question 4

communicable

Answer 4

= infectious disease transmitted from person to person by direct contact with an infected individual

Question 5

non-communicable

Answer 5

= disease isn’t capable of spreading from person to person
- 4 main types: diabetes, cancer, chronic respiratory disease, and cardio-vascular

Question 6

epidemic

Answer 6

= sudden increase of a disease above what is normally expected in that population
- disease attacks many people at the same time and speeds in restricted geographical areas

Question 7

endemic

Answer 7

= a disease which exists permanently in a geographical area or population group
- e.g. sleeping sickness confined to rural areas in sub-Saharan Africa

Question 8

pandemic

Answer 8

= an extensive epidemic - more widespread, affecting many countries and continents
- e.g. black plague in mid 14th century, COVID

Question 9

epidemiology, what does it depend on?

Answer 9

= study that helps to analyse patterns/causes/effects of disease
- depends on DEMOGRAPHICS AND AVAILABILITY OF RESOURCES

Question 10

neighbourhood effect

Answer 10

= probability of contact between a carrier and non-carrier is determined by the number of people living in each 5*5km grid square and their distance apart = DISTANCE-DECAY FUNCTION + example of EXPANSION diffusion

Question 11

why does distance-decay become less important overtime?

Answer 11

due to networks evolving and more efficient tech/transport means that the once distance parts of the world move even closer together

Question 12

facilitating spread

Answer 12

• airports (airborne)
• cargo-ships (more in Acs due to increase amount of trade)
• heavily population areas (e.g. slums and natural disaster camps)

Question 13

barriers to diffusion PHYSICAL

Answer 13

• climate
• distance/ remoteness= bodies of water/deserts/mountains (often too cold for diseases to survive)
• restriction of in and out migration

Question 14

barriers to diffusion HUMAN

Answer 14

• international border controls
• sparsely populated areas
• management via mass vaccination programmes/ heightened awareness of improved hygiene/ cancelation of large public events

Question 15

what model shows the cumulative number of cases as time goes on?

Answer 15

the HAGERSTRAND MODEL

Question 16

the 4 main stages of the Hagerstrand model?

Answer 16

1) PRIMARY STAGE
- outbreak is slow as starts from a fixed point

2) EXPANSION STAGE
- rapid growth due to contageous diffusion in population (flows of people), rate of infection increase rapidly

3) CONDENSATION STAGE
-spread slows as population becomes immune/already infected/vaccinations and other barriers to diffusion take over

4) SATURATION STAGE
- diffusion/spread stops (most infected)

Question 17

different curves to Hagerstrand model?

Answer 17

• better policies e.g. wearing face masks or v. programmes
• varies based on size of population and density of population

Question 18

hierarchical diffusion

Answer 18

= spreads through an ordered sequence of places: large city centres with high connectivity and contact -> isolated and smaller villages
-road/rail/air travel all facilitate network
e.g. 2009 when H1N1 became a pandemic due to International al flights and airports

Question 19

network diffusion

Answer 19

= diseases spread by transportation and social network

Question 20

expansion diffusion

Answer 20

• most common and traditional
  = disease has a source, carriers in source area remain infected but disease expands into new areas
• likely to weaken as expands
  e.g. H1N1 flu virus sourced in Mexico

Question 21

relocation diffusion

Answer 21

= disease leaves origin and moves into a new area
e/g/ cholera epidemic Haiti 2010 originated in Nepal, only relocated due to International aid workers flying over to tackle effects of earthquake

Question 22

contagious

Answer 22

= class of infectious diseases which are easily spread by direct or indirect contact between people
- strongly influenced by distance

Question 23

zoonotic

Answer 23

= infectious diseases of animals e.g. rabies and the plague, which can cause a disease when transmitted from animals to humans

Question 24

patterns of malaria

Answer 24

Infectious disease in Africa, Latin America, SE Asia
- spread my mosquitos that thrive inward and humid conditions => equatorial and mountain ranges or cool/dry areas unaffected

Question 25

patterns of HIV/AIDS

Answer 25

Infectious through bodily fluids. Global distribution highly uneven as depends on cultural attitudes and access to contraception

Question 26

patterns of TB

Answer 26

Highly contagious, associated with poverty and overcrowded conditions (Africa)

Question 27

patterns of diabetes

Answer 27

NCD widespread global disease in many levels of development, but concentration in N America and SE ASEA
- type 2 linked with poor diet, obesity and physical inactivity
- type 1 is genetic

Question 28

patterns of cardiovascular (CVDs)

Answer 28

Incidence rises steeply with age and mainly in Acs
- deaths linked to tobacco consumption and unhealthy diets
e.g. coronary heart disease and strokes