1a Disease Intro

Question 1

Disease definition

Answer 1

Any harmful deviation from the normal structural or functioning state of an organism

Question 2

Diffusion definition

Answer 2

The process by which diseases spread outwards from their origin

Question 3

Communicable definition

Answer 3

An infectious disease transmissible from person to person by direct content with an affected individual; the individuals discharge or indirect means (such as a vector)

Question 4

Non communicate disease

Answer 4

Also known as chronic diseases
Diseases not passed person to person.
Characterised by long duration and slow progress.
The 4 main types are CVDs, cancers, chronic respiratory diseases and diabetes

Question 5

Contagious definition

Answer 5

A class of infectious disease which are easily spread by direct contact (e.g. sharing of bodily fluids) or indirect contact (e.g. coughing)

Question 6

Non-contagious definition

Answer 6

Not spread by contact; normally require a special mode of transmission (such as vectors) or by non casual transfer of bodily fluid (such as blood transfusions or sharing needles)

Question 7

Epidemic definition

Answer 7

Often sudden increase of a disease above what is normally expected in a population. The disease attacks many people at the same time and spreads through a population in a restricted geogrpahical area

Question 8

Endemic definition

Answer 8

A disease which exists permanently in a geographic area or population group. Examples include sleeping sickness, confined to rural areas if sub Saharan Africa

Question 9

Pandemic definition

Answer 9

An extensive epidemic - a pandemic is more widespread occurrence of a new disease affecting many countries or continents.

Question 10

Classification of Malaria

Answer 10

Infectious
Non contagious
Communicable
Endemic
Epidemic

Question 11

Classification of HIV

Answer 11

Infectious
Contagious
Communicable
Endemic
Pandemic

Question 12

Classification of cholera

Answer 12

Infectious
Contagious
Communicable
Endemic
Epidemic

Question 13

Classification of Ebola

Answer 13

Infectious
Contagious
Communicable
Endemic
Epidemic

Question 14

Expansion diffusion

Answer 14

Disease spreads out from source in all directions from point of origin
Diffuses outwards into a nearby vicinity
Carriers in the source area remain infected

Question 15

Expansion diffusion example

Answer 15

TB in East Asia
Clustering of some of the 22 high burden countries which account for 80% of all TB cases

Question 16

Relocation diffusion

Answer 16

Disease spreads into new areas leaving the origin of the disease behind.
Disease is not contracted in areas between source and new area.
Disease dies out in previous location

Question 17

Relocation diffusion example

Answer 17

Cholera in Haiti originated in Nepal
Brought over by aid workers after the 2010 earthquake

Question 18

Contagious diffusion

Answer 18

Disease is spread through direct contact
Individual hosts carrying the disease pass it on to new contacts
Strongly influenced by distance (distance decay)
Contagious speeds tend to occur in a centrifugal manner from the source region outwards

Question 19

Contagious diffusion example

Answer 19

Ebola in West Africa 2014-15

Question 20

Hierarchical diffusion

Answer 20

Disease spreads down through a particular system
Disease spreads through an ordered system of classes or places, usually from the largest centres with highest connectivity to smaller more isolated centers
Diffusion is also channeled along road, rail and air transport networks which facilitate contact between carriers and susceptible populations.

Question 21

Example of hierarchical diffusion

Answer 21

H1N1 started in Mexico city but spread to other large cities (NY, LA, Chicago( before contacted to smaller cities and rural towns.
2009

Question 22

Mutation - antigenic shift

Answer 22

When two or more known strains of a virus combined to form a new strain

Question 23

Time space compression

Answer 23

globalisation resulting in distances between places appear to contract because of changes like ease of transport and communication between these placed de to increased global connectivity . This allows diseases to spread more quickly.

Question 24

Hägerstand model of diffusion

Answer 24

4 steps: primary step, expansion step, condensation step and saturation step.
Shows the unequal case load and diffusion rate across time and how a pathogen spreads.
Can be applied to Ebola in Liberia 2014/15

Question 25

Herd immunity definition

Answer 25

When a high percentage of the population is protected through vaccination against the virus or bacteria making it difficult for a disease to spread because there are so few people susceptible left effect.

Question 26

Neighbourhood effect

Answer 26

The probability of contact between the carrier and non carrier is determined by the number of people living in a 5 km x 5 km area, and their distance apart.
People living in proximity do carriers have a greater probability of contracting the disease than those further away