Diseases

Question 1

What is a disease?

Answer 1

Something that produces specific symptoms

Question 2

What is an infectious disease?

Answer 2

Spread by pathogens
Bacterial, viruses, parasites, fungi

Question 3

What is a contagious disease?

Answer 3

Infectious and spreadable
Bacterial and viral diseases

Question 4

What is a non- contagious, infectious disease?

Answer 4

Can’t be passed on from person to person
Malaria- spread by vectors

Question 5

What does communicable mean?

Answer 5

Can be spread

Question 6

What is a zoonotic disease?

Answer 6

Animals to humans
Rabies, plague
60% of infectious diseases are spread from animals

Question 7

What is an endemic?

Answer 7

Exists permanently in a geographical area or population group
Sleeping sickness- rural areas in sub saharan Africa
Chagas disease- Central and South America

Question 8

What is an epidemic?

Answer 8

Outbreak of a disease that attacks many people at the same time in a restricted geographical area
Ebola- West Africa March 2014

Question 9

What is a pandemic?

Answer 9

Spread worldwide
Black death- mid 14th century (killed 75-200 million people)
Spanish flu- 1918-19 (killed 50 million people)
Covid 19

Question 10

What are degenerative diseases?

Answer 10

The function or structure of the affected tissues or organs changes for the worst over time
Accounts for 70% of death
Ostreoarthritis, Alzheimer disease
CVD, Cancer
16 mill worldwide died from degenerative diseases
Linked to unhealthy diets, physical inactivity, smoking, alcohol
Negatively correlated with income

Question 11

What is disease diffusion?

Answer 11

The process of diseases spreading outwards from their origin region

Question 12

Disease expansion

Answer 12

Diseases spread outwards into new areas but the carriers of the disease remain infected

Question 13

Disease relocation

Answer 13

When a disease leaves the origin and moves to new areas
Cholera epidemic in Haiti, 2010 killed 7000 people
Originated in Nepal and was brough to Haiti by international workers flown in to tackle the Earthquake

Question 14

Contagious

Answer 14

Spread through the direct contact with the carrier
Strongly influenced by distance
Ebola epidemic 2014-15

Question 15

Hierarchal

Answer 15

Spreads through an ordered sequence of places.
Road, rail and air transport networks
2009 Swine flu became a pandemic via international flight routes in the USA resulting in 61 million cases and 125,000 deaths
Covid- summer 2020 killed 700,000

Question 16

Physical barriers to diffusion

Answer 16

Most important barrier is distance
Mountains, seas, deserts and climate
Climate- distribution of diseases such as malaria and sleeping sickness

Question 17

Socio-economic barriers

Answer 17

Political borders check the international movement of carriers of infectious disease
Face masks, vaccines, cancelling public events, health education

Question 18

Hagerstrand model

Answer 18

1) Primary step- beginning of diffusion
2) Expansion step- the disease develops
3) Condensation step- disease becomes more widespread
4) Saturation step- Disease is at its most widespread, Levels off as most of the population now exposed

Question 19

What is the neighbourhood effect?

Answer 19

People living in close proximity to carrier have a greater probability of contracting a disease

Question 20

How does temperature influence diseases?

Answer 20

Mosquitos thrive in warm humid conditions.
Influences cycle of Aede mosquitos
Sustained temps of 32 degrees trigger waves of Dengue epidemics (Dengue fever)
Malaria, yellow fever, sleeping fever

Question 21

How does rainfall influence diseases?

Answer 21

Exceptional rainfall evets can influence Dengue disease
Water from wells which the developing world relies on can become stagnent and dirty- diseases thrive in these conditions
Ponds allow insects and vectors to flourish
Cholera and Guinea worm

Question 22

How does relief influence diseases?

Answer 22

Altitude causes abrupt changes in climate
Ethiopia- Malaria highly concentrated in humid lowlands but largely absent in cooler highlands

Question 23

How does season influence diseases?

Answer 23

Vectors such as mosquitos thrive in warmer seasons.
Northern hemisphere- epidemics of influenza peak in winter months (5 degrees)
Mosquitos, flies, ticks and worms often peak during rainy seasons
Diarrhoeal diseases in South Asia surges in pre and end monsoon seasons

Question 24

West Nile virus

Answer 24

First identified in Uganda in 1937
Transmitted by Culex mosquitos
Birds are main host
Spread globally
Higher temps favour transmission- Texas one of the most affected states

Question 25

Lyme disease

Answer 25

Climate change is responsible for spread Transmitted by ticks In the USA, Lyme disease is expanding Northwards

Question 26

Sleeping sickness

Answer 26

Endemic in 36 sub saharan countries and affects 7 million people Transmitted by Tsetse fly 20.7-26.1 degrees Future climate change will affect the vector growth