1.a. Diseases can be classified and their patterns mapped. The spread of diseases is complex and influenced by a number of factors

Question 1

8 different disease classifications

Answer 1

• infectious
• contagious
• communicable
• non infectious (non communicable)
• epidemic
• pandemic
• endemic
• zoonotic
• degenerative

Question 2

What are infectious diseases

Answer 2

• spred by pathogens such as bacteria, viruses and parasites

- malaria- spread by disease vectors

Question 3

What are contagious diseases

Answer 3

• a class of infectious disease easily spread by direct or indirect contact between people
• bacterial infections e.g. plagues and viral diseases e.g. ebola

Question 4

What are zoonotic diseases

Answer 4

• infectious diseases spread from animals to humans

- plague, rabies

Question 5

What are non infectious diseases

Answer 5

• spread from person to person
• have causes related to lifestyle e.g. heart disease; to nutritional deficiences e.g. rickets; to genetic inheritence e.g. heart disease

Question 6

What are communicable diseases

Answer 6

-infectious diseases which spread from person to person but do not require quarantine

Question 7

What is an epidemic

Answer 7

• attacks many people and spreads through a restricted geograpical area quickly
• ebola outbreak 2014- over 25,000 people were infected across Liberia, Sierra Leone and Guinea

Question 8

What is an endemic

Answer 8

• exists permanently in an area
• this may be within a geographical area or within a population group
• Chagas disease was transmitted by ticks found in small communities in central and South America. It affects 7.6 million people

Question 9

What is a pandemic

Answer 9

• an epidemic that spreads worldwide

- Bubonic plague of the mid 14 century, 1918-19 Spanish Flu and COVID 19 are examples

Question 10

What is a degenerative disease

Answer 10

• over 60% of worldwide deaths-due to global ageing population and increaseingly unhealthy lifestyles
• CVD and cancer are examples

Question 11

Name a couple diseases which were the main causes of death in the UK

Answer 11

• coronary heart disease
• stroke
• lung cancer
• influenza

Question 12

Example of a pandemic- Spanish Flu 1918-1919- statistics

Answer 12

• caused 20-50 million deaths worldwide
• only about 1% infected with the virus died
• H1N1 type A influenza
• at least 10% of patients died

Question 13

Example of a pandemic- Spanish Flu 1918-1919- location

Answer 13

• first identified in military personnel in Spring 1918 in US
• first reported cases in Spain
• virus spread by soldiers returing home from trenches in northern Fran. Then spread to UK

Question 14

Example of a pandemic- Spanish Flu 1918-1919- transmission

Answer 14

• person to person through airborne resipartory secretions
• can occur if a new strain of influenza emerges against which the population has no immunity
• contagious

Question 15

Example of a pandemic- Spanish Flu 1918-1919- symptoms

Answer 15

• first wave: typical flu symptoms

- second wave: skin turned blue, lungs filled with fluid

Question 16

Example of a pandemic- Spanish Flu 1918-1919- mitigation strategies

Answer 16

• buildings converted into hopsitals
• doctors prescribed medication
• isolation and quarantine
• good personal hygiene
• disinfectants

Question 17

Global distribution of Malaria- worst affected countries and continent

Answer 17

• countries- Nigeria, Demographic Republic of Congo

- continent- Africa

Question 18

Global distribution of HIV/AIDS- worst affected countries and continent

Answer 18

• countries- Sub-Saharan Africa, Ethiopia, India

- continent- Southern Africa

Question 19

Global distribution of Tuberculosis- worst affected countries and continent

Answer 19

• countries- India, Indonesia, China, Nigeria

- continent- Asia

Question 20

Global distribution of Diabetes- worst affected countries and continent

Answer 20

• countries- North America, China, India

- continent- Asia

Question 21

Global distribution of CVD- worst affected countries and continent

Answer 21

• countries- Turkmenistand, Ukraine

- continent- Russia, Sub-Saharan Africa

Question 22

What is disease diffusion

Answer 22

the process by whcih a disease spreads outwards beyone its geographical source

Question 23

What is expansion diffusion

Answer 23

• the disease has a source and spreads outwards into new areas
• carriers in the source remain infected
• outbreaks of TB diffuse in this way

Question 24

What is relocation diffusion

Answer 24

• when a disease leaves an rea of origin and moves into new areas
• the Cholora epidemic in Haiti, 2010 diffused in this way after being brought to the country by aid workers from Nepal

Question 25

What is contagious diffusion

Answer 25

• describes the spread of a disease through direct contact with a carrier
• it is heavily influenced by distance
• Ebola outbreak in West Africa2014-15 is an example

Question 26

What is hierachical diffusion

Answer 26

• describes when a disease spreads through a sequenced order by places
• usually spreads in larger urban centres and dissusions outwards to highly connectm smaller and more remote centres
• H1N1 influenza virus pandemic of 2009 is an example

Question 27

Physical barriers which are barriers to diffuse to stop the spread of disease

Answer 27

• distance- probability of a contagious disease spreading to an area is inversely proportional to distance from its source
• mountain ranges, seas, oceans, deserts
• climate- major factor in epidemiology and distribution of diseases

Question 28

Socio-economic barriers which are barriers to diffuse to stop the spread of disease

Answer 28

• political border check the international movement of carriers
• imposing curfews to limit contact between people- Ebola virus in Sierra Leone
• quarantining of western aid workers
• wearing masks
• csncelling public events
• mass vaccination to protect populations
• health education

Question 29

What is the purpose of Hägerstrand’s diffusion model

Answer 29

• developed to stimulate the spread of farm subsidies in Southern Sweden
• later, the model was applied to the contagious diffusion of diseases

Question 30

What are the three concepts of Hägerstrand’s diffusion model

Answer 30

• neighbourhood effect- probability of contact between a carrier and non carrier is determined by the number of people living in each 5kmx5km grid square and their distance apart. People living in proximity to carrier have a greater probability of contracting a disease
• the number of people infected by an epidemic approximated an S shape over tine (logistic curve)
• progress and diffusion of a disease may be interruputed by physical barriers

Question 31

Briefly explain Logistic curve

Answer 31

after a slow beginning, the number accelerates until leveling out (s shape)

Question 32

Explain