1a.3 How do diseases spread to new areas?
How do diseases spread to new areas?
Objects in the environment that prohibit interaction (and therefore spread) from taking place.
Most important barrier is distance.
As distance increases, chance of contraction decreases.
Socio-economic barriers prohibit diffusion when a person's beliefs, culture, wealth or place in society prohibit interaction with certain people or places.
Access to healthcare
Not eating certain foods
Barriers used to limit spread of disease
Cancelling public events
Access to condoms
Disease has a source and spreads outwards into new areas.
Carriers in the source remain infected, and the rate of disease often intensifies.
Outbreak of TB
Spread of disease through direct contact with a carrier.
It is strongly influenced by distance because nearby individuals/regions have a much higher probability of contact with disease than remote individuals or regions.
Disease spread through an
of places, usually from the largest centres with the highest connectivity to smaller, more isolated centres.
channeled along road, rail, and air transport networks
which facilitate contact between carriers and a susceptible population.
H1N1 flu virus became a pandemic via international flight routes and airports.
When a disease leaves the area or origin and moves into new areas.
Migration of disease carriers.
Movement of a person with HIV.
Occurs when a disease spreads via transportation and/or social networks.
Diseases spread outwards from their origin and
in a process.
The spread of a disease is a mixture of types if disease diffusion.