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

Infections disease

Spread by pathogens such as bacteria, viruses and parasites, most can be transmitted from one person to another

Malaria

Non-infectious disease

Not communicable

Communicable disease

Infectious diseases which spread from one person to another but do not require quarantine

Non-communicable disease

Not spread from person to person but have causes related to lifestyle (heart disease, cancer), nutritional diseases (rickets), genetic inheritance (heart disease)

Contagious disease

A class of infectious disease spread easily by direct or indirect contact between people, eg typhoid or ebola

Non-contagious disease

Cannot be spread between people

Epidemic

A disease outbreak that attacks many people at the same time and spreads through a population in a restricted geographical area.

Endemic

Exists permanently in a geographical area or population (sleeping sickness in rural areas of sub-Saharan Africa

Pandemic

Epidemic that spreads globally

Zoonotic

Infectious disease transmitted from animals to humans (rabies, plague)

Where is malaria found, how is it transmitted.

Found in Africa, Latin America, South and Southeast Asia because it thrives in warm and humid environments. Effective prevention measures mean that is it not present in the US and South.

It is transmitted via the Anopheles Mosquito, it is infectious but not contagious.

Where is HIV/AIDS found, why, how is it transmitted

Unevenly spread but main concentrations are in sub Saharan Africa. South Africa and Nigeria have the largest numbers and in Swaziland and Lesotho, more than a quarter of the population have the disease, it is transmitted through bodily fluids such as blood ans semen. It is infectious and contagious.

Where is tuberculosis found, why, how is it transmitted

Found largely in Africa, Afghanistan, Myanmar, Cambodia. This is due to poverty and overcrowded living conditions. It is transmitted through air borne droplets eg, coughing. It is infectious and contagious

Where is type 2 diabetes found, why, how is it transmitted

Diabetes is found in both developed and ess developed countries but is most strongly concentrated in North America and South and East Asia. This is due to rising disposable income and sedimentary jobs. It is non-communicable.

Where is cardiovascular disease found, why, how is it transmitted

CVD is found in Russia, sub-Saharan Africa and the Arabian peninsula. This is linked to lifestyle eg smoking, diet and physical inactivity

Main cause of death in developed areas

Non-infectious diseases

Expansion diffusion

The disease has a source and spreads outwards into new areas, the source area remains infected.

Relocation diffusion

The disease leaves the area of origin and moved into new areas

Contagious diffusion

The disease is spread through direct contact with a carrier

Hierarchal diffusion

Disease spreads through a structures sequence of locations, usually from large, well connected centres to smaller, more isolated centres.

Neighbourhood effect

Th probability of contact between those infected and those not infected and the influence of distance decay

Distance decay

Spread of contagious disease follows a distance decay pattern with infection rates highest near the where the outbreak is and declining further away

Primary stage of Hägerstrand’s model

There is a strong contrast in disease incidence in the area of the outbreak compared to remote areas

Diffusion stage of Hägerstrand model

New centres of disease outbreak occur at distance from the source and this reduces the primary stages spatial contrast

Condensing stage of Hägerstrand model

Diffusion decelerates as the incidence of the disease reaches its peak

Physical barriers

Distance, mountains, sea, deserts, climate change

Socio economic barriers

Politcal borders, curfews, quarantining

Difference between an infectious and contagious disease

Infectious disease is spread by pathogens eg bacteria and viruses. Contagious disease is a class of infectious disease easily spread by direct or indirect contact with people

Define hierarchal disease diffusion

The disease spreads through a structures sequence of locations from large, well connected centres to smaller isolated centres - eg cities to villages

Key phases of the Hägerstrand diffusion model

Primary, diffusion, condensing and saturation.

Hoe does climate change affect patterns of disease

Altitude leads to falling temperatures and increasing rainfall. In parts of Africa, at high altitudes it is too cold or mosquitoes. Flat floodplains can lead to diseases during periods of flood in low-income countries.

How do water sources affect the patterns of disease

Stagnant water affects the prevalence of water borne disease, parasitic worms in infected water spread disease.

How does rainfall affect vectors of disease

Creates puddles at the end of the rainy season, can also wash away the larvae of mosquitoes.

How does temp affect vectors of disease

Vectors are active in places where average temperates are between 18 ad 40 degree Celsius

How does humidity affect vectors of disease

Vectors like humidity over 60%

How do seasonal variations influence influenza and respiratory illnesses

Peak in winter moths in the northern hemisphere

How do seasonal variations influence fly populations

They are the highest in South Asia in the pre-monsoon and end of monsoon seasons

How do seasonal variations influence sleeping sickness

The tsetse ply can live longer in the wet season

Two ways climate change can influence pattern of disease

Climate affects where vectors of disease live eg mosquitoes in humid tropics; low levels of sunlight can lead to diseases derived from deficiency of vitamin D, cold damp climates can lead to a prevalence of respiratory disease.

How can relief affect patterns of disease

Altitude - increasing altitude, temperature falls, meaning there are fewer mosquitoes. On flat floodplain, standing water can become polluted snd spread disease (stagnant)

Explain one seasonal influence on disease outbreaks

Epidemics of influenza and respiratory illness peak in the winter moths in the northern hemisphere. Vector borne diseases transmitted by mosquitoes , flies and ticks peak during the rainy season in the tropics and sub-tropics. Fly populations are the highest in South Asia in the pre-monsoon and end of monsoon seasons. The tsetse fly, which transmits sleeping sickness in the west and central Africa can live longer in the wet season, making more frequent transmissions.

Where are zoonotic diseases prevalent

Where there is free movement of infected animals, urbanisation that creates habitats for foxes, bringing them into closer contact with humans. There is not an effective vaccination program for pets and livestock. Hygiene and sanitation are poor. There is a prolonged close contact between human and animals eg farms

How do rising economic and social development influence a country’s epidemiological tradition

As countries develop, the health and well being of the nations should also improve as more money is available to spend on agriculture, health, services and basic infrastructure

How does economic development help a countries epidemiological transition

Investment in agriculture to raise yields and farming efficiency in order to provide adequate good-quality food. Improved infrastructure so food can be stores and distributed efficiently. Investment in healthcare

How does social development help a countries epidemiological transition

Better education on sanitisation and diet and the spread of the diseases. Advances in medical care and availability of medicines and vaccinations. Better education. Reduced infant mortality.

What does Abdel Omran’s epidemiological transition model state

Over time as a country develops there will be a transition from infectious diseases to chronic and degenerative diseases as the main cause of death

4 stages of epidemiological transition model

Age of infection and famine

Age of reducing pandemics

Age of degenerative and man-made diseases

Age of delayed degenerative diseases

Describe the age of infection and famine

Poor sanitation and hygiene, unreliable food supply. Death is caused by infections and malnutrition.

Describe the age of reducing pandemics

Improved sanitation and better diet. Reduced number of infections and increases in occurrence of strokes and heart disease.

Describe the age of degenerative and man made diseases.

Increased ageing, lifestyles associated with poor diet and less activity and addictions. Deaths caused by high blood pressure, obesity, diabetes, cancers, strokes, heart disease.

Describe the age of delayed degenerative diseases.

Reduced risk behaviours in the population, health promotion and new treatments. Deaths caused by heart disease, strokes and cancers but treatment extends life.

Why do LIDCs have a higher prevalence of communicable diseases and ACs have a higher prevalence of non communicable diseases?

Communicable diseases have been eliminated in ACs through treatment and standards of living. Prolonged life in ACs mean that degenerative illnesses have increased. ACs have higher overnutrition and excess consumption of sugar, fats and salts. Tropical and sub-tropical locations is where communicable diseases and vector borne diseases are present. Poverty and lack of resources and hygiene are also a factor.

What do the WHO do

The WHO carry out data collection, leadership in health matters, technical support and research and monitoring.

What does rosy periwinkle help with

Wasp stings in India, Diabetes in China. It contains vinblastine which is an effective treatment of Cancer.

What is biopiracy

The stealing of medicinal plants from their native country by a foreign body who profits from it but doesn't channel any of the money back to the source country.

How do women play a role in battling disease

They are often primary carers for children and are key to understanding and using vaccinations and health awareness. Female frontline health workers have a greater impact on education and vaccination programmes than male workers due to relating to other women better.

Women also prepare food and poor practice can cause disease to spread.