Disease Dilemmas
Key Idea 1 = What are the global patterns of disease and can factors be identified that
determine these?
1.a Disease can be classified and their patterns mapped. The spread of diseases is complex
and influence by a number of factors:
Top 10 causes of mortality:
1. Heart disease = 13% 2000 - 2.7 million to 2021 - 9.1 million deaths = high fatty foods and
obesity = sedentary lifestyle
2. Covid 19 = 777 million cases, 8.8 million deaths
3. Stroke = 10%
4. Chronic obstructive pulmonary disease = 4%
5. Lower respiratory infections = 2021 2.5 million, 400,000 lower than 2000
6. Trachea, bronchus, lung cancers = 1.2 million in 2000 to 1.9 million 2021 = smoking and
vaping
7. Alzheimer disease and other dementias = 3.9%
8. Diabetes mellitus
9. Kidney diseases
10. Tuberculosis
Pattern of disease spread:
• Heart diseases seems to be primarily focussed around Acs and EDCs such as North
America, Russia, Australia, UK and Europe
• HIV and AIDS aswell as tuberculosis which is a communicable disease are focused in LICs
within sub-Saharan-Africa
• Cancers are also focussed in EDCs and Acs including China, Portugal, Spain and France
Factors that influence this:
• Development patterns
• Population density
• Government and healthcare capacity
Classifying diseases:
Infectious A disease caused by pathogens that can invade and multiply within the
body
Communicable An infectious disease that can be transmitted from one person to another or
animals to people
Non Opposite of above e.g Rickets, Heart Disease, Type 2 diabetes, Stroke +
communicable cancer (from lifestyle, nutrition and inheritance)
Contagious A type of communicable disease that spreads very easily through direct
contact, droplets, proximity
Epidemic A sudden increase in the number of cases of a disease within a specific
population or areas above what is normally expected
, Endemic A diseases that is constantly present within a region or population at a
relatively stable rate
Pandemic An epidemic that spreads across multiple countries or continents -
affecting a large number of people = globally
Zoonotic A disease that originates in animals and can be transmitted to humans
Mortality The number of deaths in a population, often expressed as a rate
Morbidity A level of illness, disease or poor health often measure by prevalence or
incidence
Infant mortality The number of deaths of children under 1 year per 1,000 live births in a given
rate year
Life expectancy The average number of years a person is expected to live based on current
mortality patterns
Degenerative A disease in which the function or structure of tissues or organs
disease progressively deteriorates over time = associated with ageing
Epidemiology The branch of medicine which deals with the incidence, distribution and
possible control of diseases and other factors relating to health
Vector The mosquito, sand fly etc.. which carries a pathogen
Prevalence Total n.o cases in a population at a particular time
Incidence of The number of new cases in a population during a particular time period
disease
Global variations:
• Historically, contagious diseases have been the biggest killers worldwide.
• They are still important in the developing world but kill very few people in the developed
world.
• In developed countries non-infectious/contagious diseases are the main cause of death.
CVD and Cancers account for about 2/3 of premature deaths in the UK.
• Deaths from non-infectious/contagious diseases are increasing in the developing world as
standards of living rise.
,Temporal changes:
• Non communicable diseases have risen from 55% to 72% from 1990 to 2017 whereas
communicable diseases have decreased over that period.
Global distributions of malaria, HIV, tuberculosis, diabetes and cardio-vascular disease:
Malaria:
• 2017 = estimated 3.3 billion ppl across 97 countries at risk of malaria
• 2018 = 214 million cases of malaria worldwide in estimated 405,000 deaths - compared to
451,000 in 2016 - 607,000 in 2010
o Overall deaths from malaria are going down
• Children under 5 are most vulnerable group affected by malaria - 2017 accounted for 61%
of all malaria deaths worldwide (266,000)
• WHO African Region accounted for 93% of all malaria deaths in 2017
o Although WHO African Region + India was home to highest number of malaria
deaths in 2017
o Accounted for 88% of 172,000 fewer deaths reported in 2017 than 2010
• Nearly 80% of global malaria deaths in 2017 were concentrated to 17 countries in WHO
African Region + India
o 7 of these accounted for 53% for all global malaria deaths: Nigeria 19% - Congo
11% - Burkina Faso 6% - Tanzania 5% - Sierra Leone 4% - Niger 4% - India 4%
• All WHO regions except WHO Regions of the Americas recorded reductions in mortality in
2017 compared with 2010
o Largest declines occurred in WHO regions of South-East Asia 54% - Africa 40% -
Eastern Mediterranean 10%
o Despite these gains malaria mortality reduction rate has slowed since 2015
reflecting estimated trends in malaria case incidence
HIV:
• The distribution of people dying from HIV is varied and highly uneven, notably with a high
concentration in Africa - since 720,000 died in 2016 from HIV related causes. This contrasts
with Europe, where 49,000 people died in 2016, and the area with the least amount of HIV is
the Eastern Mediterranean area, with countries such as Saudi Arabia and Egypt having
17,000 deaths in 2016.
• Some examples include South Africa and Nigeria which have the largest numbers of
HIV/AIDS cases, while in Swaziland and Lesotho more than a quarter of the population
carry the disease.
• The likely reason for HIV related deaths being highly concentrated in Africa is due to the
lack of healthcare in several developing sub-Saharan African countries - with vaccines and
preventative measures being limited or lacking hygiene.
• Furthermore, developing countries may have several people living in close conditions and
sharing supplies such as water and food amongst a large number of people, which would
increase the spread of infectious diseases significantly. Healthcare in these developing
countries may also lack sanitisation, with there being a higher chance of infected needles
and syringes spreading the disease. This is why there is also a significantly high number of
people in other developing countries such as India and Indonesia dying from HIV - with
them both having 130,000 deaths in 2016.
• However in contrast, areas such as Europe have much less HIV due to the advanced
healthcare which would provide vaccines and treatment reducing the risk of death from
, HIV, as well as having higher levels of education which would increase awareness of how to
prevent the spread of HIV.
• Also, areas in the Middle East such as Saudi Arabia also have lower levels of HIV related
deaths, possibly due to societal norms and cultural differences limiting the number of
people who have sexual relations, reducing the risk of HIV spreading significantly.
Tuberculosis:
STATISTICS + distributions:
• In 2015, 10.4 million people fell ill with TB and 1.8 million died from the disease. TB mostly
affects adults in their most productive years - but all ages at risk. Over 95% of cases and
deaths are in developing countries.
• Tobacco use also greatly increases the risk of TB disease and death. More than 20% of TB
cases worldwide are attributable to smoking
• total of 1.5 mill died from TB in 2018 - 251,000 people with HIV
• 2018 - 30 high TB countries accounted for 87% of new TB causes - India, China, Indonesia,
Philippines, Nigeria, Bangladesh, South Africa
• Multidrug resistant TB = public health crisis -WHO estimated 484,000 new cases with
resistance to rifampicin - most effective first - line drug, of which 78% had MDR - TB
• Globally = TB Incidence falling 2% per year
• 58 million lives were saved through TB diagnosis + treatment between 2000 - 2018
ending the TB epidemic by 2030
TB 2004 MORTALITY PATTERNS
• Sub Saharan Africa = highest TB deaths (>50,000) + South Asia India, China, Indonesia, South
Africa = particularly high TB mortality
• lower mortality (<10,000 deaths) in Europe, North America, Aus
• highest research outputs on TB come from high income (USA, UK, Germany, Japan, France)
• India + China are exceptions - contributing to significant research while also having high TB
incidence
Overall = TB deaths heavily concentrated in poorer regions, while research productivity
concentrated in richer countries
TB 2016 PATTERNS :
• Highest TB incidence = Sub Saharan Africa (South Africa, Mozambique, Angola) rates exceed
300 per 100,000 high rates in South Asia (India, Pakistan, Bangladesh) + parts of South East
Asia
• moderate rates (100-199 per 100,000) are found in China, Russia and Middle eastern
countries
• Low incidence dominates North America + Western Europe, AUS + NZ = highest in low
income tropical countries, lowest in wealthy temperate
Factors affecting the global patterns of TB incidence:
LEVEL OF DEVELOPMENT
- LICs in Sub Sharan Africa, South Asia = high TB incidence - poverty, overcrowded conditions,
limited healthcare budgets
- HICS in Europe, North America, AUS = low incidence - strong health systems, vaccinations,
higher standard of living, better sanitation
HEALTH CARE INFRASTRUCTURE + ACCESS
Key Idea 1 = What are the global patterns of disease and can factors be identified that
determine these?
1.a Disease can be classified and their patterns mapped. The spread of diseases is complex
and influence by a number of factors:
Top 10 causes of mortality:
1. Heart disease = 13% 2000 - 2.7 million to 2021 - 9.1 million deaths = high fatty foods and
obesity = sedentary lifestyle
2. Covid 19 = 777 million cases, 8.8 million deaths
3. Stroke = 10%
4. Chronic obstructive pulmonary disease = 4%
5. Lower respiratory infections = 2021 2.5 million, 400,000 lower than 2000
6. Trachea, bronchus, lung cancers = 1.2 million in 2000 to 1.9 million 2021 = smoking and
vaping
7. Alzheimer disease and other dementias = 3.9%
8. Diabetes mellitus
9. Kidney diseases
10. Tuberculosis
Pattern of disease spread:
• Heart diseases seems to be primarily focussed around Acs and EDCs such as North
America, Russia, Australia, UK and Europe
• HIV and AIDS aswell as tuberculosis which is a communicable disease are focused in LICs
within sub-Saharan-Africa
• Cancers are also focussed in EDCs and Acs including China, Portugal, Spain and France
Factors that influence this:
• Development patterns
• Population density
• Government and healthcare capacity
Classifying diseases:
Infectious A disease caused by pathogens that can invade and multiply within the
body
Communicable An infectious disease that can be transmitted from one person to another or
animals to people
Non Opposite of above e.g Rickets, Heart Disease, Type 2 diabetes, Stroke +
communicable cancer (from lifestyle, nutrition and inheritance)
Contagious A type of communicable disease that spreads very easily through direct
contact, droplets, proximity
Epidemic A sudden increase in the number of cases of a disease within a specific
population or areas above what is normally expected
, Endemic A diseases that is constantly present within a region or population at a
relatively stable rate
Pandemic An epidemic that spreads across multiple countries or continents -
affecting a large number of people = globally
Zoonotic A disease that originates in animals and can be transmitted to humans
Mortality The number of deaths in a population, often expressed as a rate
Morbidity A level of illness, disease or poor health often measure by prevalence or
incidence
Infant mortality The number of deaths of children under 1 year per 1,000 live births in a given
rate year
Life expectancy The average number of years a person is expected to live based on current
mortality patterns
Degenerative A disease in which the function or structure of tissues or organs
disease progressively deteriorates over time = associated with ageing
Epidemiology The branch of medicine which deals with the incidence, distribution and
possible control of diseases and other factors relating to health
Vector The mosquito, sand fly etc.. which carries a pathogen
Prevalence Total n.o cases in a population at a particular time
Incidence of The number of new cases in a population during a particular time period
disease
Global variations:
• Historically, contagious diseases have been the biggest killers worldwide.
• They are still important in the developing world but kill very few people in the developed
world.
• In developed countries non-infectious/contagious diseases are the main cause of death.
CVD and Cancers account for about 2/3 of premature deaths in the UK.
• Deaths from non-infectious/contagious diseases are increasing in the developing world as
standards of living rise.
,Temporal changes:
• Non communicable diseases have risen from 55% to 72% from 1990 to 2017 whereas
communicable diseases have decreased over that period.
Global distributions of malaria, HIV, tuberculosis, diabetes and cardio-vascular disease:
Malaria:
• 2017 = estimated 3.3 billion ppl across 97 countries at risk of malaria
• 2018 = 214 million cases of malaria worldwide in estimated 405,000 deaths - compared to
451,000 in 2016 - 607,000 in 2010
o Overall deaths from malaria are going down
• Children under 5 are most vulnerable group affected by malaria - 2017 accounted for 61%
of all malaria deaths worldwide (266,000)
• WHO African Region accounted for 93% of all malaria deaths in 2017
o Although WHO African Region + India was home to highest number of malaria
deaths in 2017
o Accounted for 88% of 172,000 fewer deaths reported in 2017 than 2010
• Nearly 80% of global malaria deaths in 2017 were concentrated to 17 countries in WHO
African Region + India
o 7 of these accounted for 53% for all global malaria deaths: Nigeria 19% - Congo
11% - Burkina Faso 6% - Tanzania 5% - Sierra Leone 4% - Niger 4% - India 4%
• All WHO regions except WHO Regions of the Americas recorded reductions in mortality in
2017 compared with 2010
o Largest declines occurred in WHO regions of South-East Asia 54% - Africa 40% -
Eastern Mediterranean 10%
o Despite these gains malaria mortality reduction rate has slowed since 2015
reflecting estimated trends in malaria case incidence
HIV:
• The distribution of people dying from HIV is varied and highly uneven, notably with a high
concentration in Africa - since 720,000 died in 2016 from HIV related causes. This contrasts
with Europe, where 49,000 people died in 2016, and the area with the least amount of HIV is
the Eastern Mediterranean area, with countries such as Saudi Arabia and Egypt having
17,000 deaths in 2016.
• Some examples include South Africa and Nigeria which have the largest numbers of
HIV/AIDS cases, while in Swaziland and Lesotho more than a quarter of the population
carry the disease.
• The likely reason for HIV related deaths being highly concentrated in Africa is due to the
lack of healthcare in several developing sub-Saharan African countries - with vaccines and
preventative measures being limited or lacking hygiene.
• Furthermore, developing countries may have several people living in close conditions and
sharing supplies such as water and food amongst a large number of people, which would
increase the spread of infectious diseases significantly. Healthcare in these developing
countries may also lack sanitisation, with there being a higher chance of infected needles
and syringes spreading the disease. This is why there is also a significantly high number of
people in other developing countries such as India and Indonesia dying from HIV - with
them both having 130,000 deaths in 2016.
• However in contrast, areas such as Europe have much less HIV due to the advanced
healthcare which would provide vaccines and treatment reducing the risk of death from
, HIV, as well as having higher levels of education which would increase awareness of how to
prevent the spread of HIV.
• Also, areas in the Middle East such as Saudi Arabia also have lower levels of HIV related
deaths, possibly due to societal norms and cultural differences limiting the number of
people who have sexual relations, reducing the risk of HIV spreading significantly.
Tuberculosis:
STATISTICS + distributions:
• In 2015, 10.4 million people fell ill with TB and 1.8 million died from the disease. TB mostly
affects adults in their most productive years - but all ages at risk. Over 95% of cases and
deaths are in developing countries.
• Tobacco use also greatly increases the risk of TB disease and death. More than 20% of TB
cases worldwide are attributable to smoking
• total of 1.5 mill died from TB in 2018 - 251,000 people with HIV
• 2018 - 30 high TB countries accounted for 87% of new TB causes - India, China, Indonesia,
Philippines, Nigeria, Bangladesh, South Africa
• Multidrug resistant TB = public health crisis -WHO estimated 484,000 new cases with
resistance to rifampicin - most effective first - line drug, of which 78% had MDR - TB
• Globally = TB Incidence falling 2% per year
• 58 million lives were saved through TB diagnosis + treatment between 2000 - 2018
ending the TB epidemic by 2030
TB 2004 MORTALITY PATTERNS
• Sub Saharan Africa = highest TB deaths (>50,000) + South Asia India, China, Indonesia, South
Africa = particularly high TB mortality
• lower mortality (<10,000 deaths) in Europe, North America, Aus
• highest research outputs on TB come from high income (USA, UK, Germany, Japan, France)
• India + China are exceptions - contributing to significant research while also having high TB
incidence
Overall = TB deaths heavily concentrated in poorer regions, while research productivity
concentrated in richer countries
TB 2016 PATTERNS :
• Highest TB incidence = Sub Saharan Africa (South Africa, Mozambique, Angola) rates exceed
300 per 100,000 high rates in South Asia (India, Pakistan, Bangladesh) + parts of South East
Asia
• moderate rates (100-199 per 100,000) are found in China, Russia and Middle eastern
countries
• Low incidence dominates North America + Western Europe, AUS + NZ = highest in low
income tropical countries, lowest in wealthy temperate
Factors affecting the global patterns of TB incidence:
LEVEL OF DEVELOPMENT
- LICs in Sub Sharan Africa, South Asia = high TB incidence - poverty, overcrowded conditions,
limited healthcare budgets
- HICS in Europe, North America, AUS = low incidence - strong health systems, vaccinations,
higher standard of living, better sanitation
HEALTH CARE INFRASTRUCTURE + ACCESS
