Disease Dilemmas (DD) Flashcards
1
Q
Disease:
A
A disorder of structure or function in a human, especially one that produces specific symptoms to that affects a specific geographical area and is not simply a direct result of physical injury.
2
Q
Infectious:
A
Spread by pathogenic microorganisms such as bacteria, viruses or parasites.
3
Q
Non-Infectious:
A
Diseases that cannot be spread by pathogenic microorganisms (usually due to diet and lifestyle)
4
Q
Communicable:
A
Infectious diseases which spread from host to host.
5
Q
What is animal to animal/animal to person spreading called?
A
Zoonotic
6
Q
Non-Communicable:
A
A non-infectious, non-contagious disease that is not transmissible among people or other hosts (e.g. cancer).
7
Q
Contagious:
A
A class of infectious disease that is easily spread by direct or indirect contact between people.
8
Q
Epidemic:
A
Disease outbreaks that spread quickly through the population of a geographical area, affecting many people at the same time.
9
Q
Endemic:
A
Disease that exists permanently in geographical area or specific human group.
10
Q
Pandemic:
A
Epidemic outbreaks that spread worldwide.
11
Q
Prevalence:
A
Proportion of cases in a population at a given time
12
Q
Incidence:
A
Occurrence of new cases.
13
Q
Mortality:
A
Incidence of death
14
Q
Morbidity:
A
Refers to the state of being diseased.
15
Q
Epidemiology:
A
Branch of medicine concerned with incidence, distribution and possible control of diseases.
16
Q
In how many countries is malaria an endemic disease?
A
95
17
Q
How does malaria come about?
A
Anopheles mosquitos lay their eggs in water, which hatch into larvae. The females seek a blood meal to nurture their eggs and in doing so, inject the parasite.
18
Q
Where is the greatest amount of malaria (percentage and country)
A
23% of malaria cases can be found in Nigeria
19
Q
How many worldwide cases of malaria are there?
A
229 million
20
Q
Why is malaria a leading cause of child mortality?
A
Because children under five are most vulnerable.
21
Q
What climate is needed for malaria and why?
A
Warm and humid environments (27 degrees) else larvae cannot complete its cycle as it will not be optimum temperature.
22
Q
Why is high rainfall crucial to malaria?
A
Large rainfall near the equator results in stagnant water for the mosquitos to lay their eggs in.
23
Q
What are two climates in which mosquitos cannot live?
A
High altitude (low temp) and dry desert (no water).
24
Q
What has been implemented to lower the risk of malaria (short answer).
A
Nets and pesticides.
25
What does HIV stand for?
Human Immunodeficiency Virus
26
What are three features of HIV?
Communicable, infectious, contagious
27
How does transmission of HIV occur?
Through bodily fluids
28
In South Africa, what percentage of the population lives with HIV?
13%
29
What two countries have the largest amount of HIV cases?
Zambia and South Africa
30
How has HIV temporally changed (short answer)?
Sharp increase in incidence in 1990s but peaked 98 with there being a decline since. Prevalence has since increased but number of deaths has gone down.
31
Why has their been progress in LIDCs regarding AIDS/HIV (short answer)?
Self testing and anti retroviral drugs (ARTs)
32
What are four features of TB?
Contagious, infectious, communicable, epidemic.
33
How is TB spread?
Bacterial infection spread through the air person to person.
34
How many people died of TB in 2019?
1.4 million
35
What percentage of TB deaths were in EDCs and LIDCs?
95%
36
What is Diabetes?
A non-communicable disease caused by the deficiency of insulin.
37
What can diabetes lead to?
Heart, blood vessel, eye and kidney damage.
38
How many diabetes cases in Western Pacific?
132 Million
39
What is temporally expected of diabetes?
That there will be a massive increase in cases by 2040.
40
What is CVD?
Cardiovascular Disease
41
Globally how many deaths does CVD account for?
17 million deaths per year
42
Why are ageing populations at risk of CVD?
Because incidence rises steeply with age.
43
Why is poverty linked with CVD
Disadvantaged people are at greater risk of being exposed to unhealthy dietary practices.
44
Disease diffusion:
The process by which a disease spreads from its geographical source.
45
What are the four types of disease diffusion?
expansion, diffusion, hierarchal, relocation
46
Expansion:
Disease spreads from one place to another forming new areas of prevalence. It also remains in the area of the outbreak.
47
Relocation:
The diseases moves to new areas but does not stay in the area of the outbreak.
48
Contagious (Diseases Diffusion):
The spread of disease through direct contact with a carrier. It is strongly influenced by the factor of distance.
49
Hierarchal:
A disease spreads through an ordered sequence of places, usually from the largest centres with the highest connectivity, to more isolated centres.
50
What model is used for disease diffusion?
Hagerstrand
51
What are the four stages of the hagerstrand model?
Primary, diffusion, condensing, saturation.
52
What shape does the hagerstrand model graph take and what is on the x and y axes?
S shaped, with cumulative % infected on the y and time on the x.
53
What is the Primary stage? (hagerstand)
Strong contrast in disease incidence in the are of outbreak and more remote areas.
54
What is the diffusion stage? (hagerstrand)
Diffusion is centrifugal, new centres of disease outbreak occur at distance from the source, this reduces the special contrast mentioned in the primary stage.
55
What is the condensing stage? (hagerstrand)
the number of new cases is equal in all locations, irrespective of distance from the source
56
What is the saturation stage? (hagerstrand)
Diffusion accelerates as the incidence of the disease reaches its peak.
57
What three important concepts does the Hagerstrand model highlight?
Neighbourhood effect, S shaped curve and barriers to disease.
58
What is the neighbourhood effect?
Probability of contact between disease carrier and non disease carrier is determined by the number of people living in each 5x5 km grid square and their distance apart. Thus, people living in proximity to carriers, have a greater probability of contracting the disease.
59
What is the S shaped curve concept?
The number of people infected by an epidemic approximates an S shaped curve.
60
What is the hagerstrand barriers to disease concepts?
Progression of disease may be interrupted by physical barriers.
61
What are 5 physical barriers to disease?
distance, high mountain ranges, large maritime areas, extensive areas of aridity and climate.
62
What are 6 socio-economic barriers to disease diffusion?
quarantines, vaccination programmes, face masks, cancelling public events, health education, medical health checks at airports.
63
What are four global patterns that impact disease patterns?
Precipitation, relief, temperature and water sources.
64
Natural hazard:
When a natural process puts human lives, infrastructure, or economic interest at risk.
65
What are the four main problems that arise due to link between disease and natural hazards?
Large number of people displaced, gathering in confined places.
Poor sanitation and water contamination.
Disruption to infrastructure = no access to healthcare.
Interruption of public healthcare programmes.
66
What is the case study linked to natural hazards and disease?
Bangladesh flooding in August 2007 causing typhoid and hepatitis.
67
What is the case study linked to natural hazards and disease?
Bangladesh flooding in August 2007 causing typhoid and hepatitis.
68
Why is flooding common in Bangladesh?
Due to annual monsoon rains and seasonal flooding of glaciers which threaten low lying deltas where three major rivers converge.
69
What percentage of Bangladesh was flooded?
60%
70
How many people were displaced after the Bangladesh flood?
9 million
71
What does deforestation of the Himalayas have to do with the Bangladesh flood?
Deforestation reduces interception rates.
72
How did climate affect the outcome of the Bangladesh flood?
High humidity and temperature and low elevation heightened the affect of the flood.
73
What does tectonic uplift of the Himalayas have to do with the 2009 flood?
Caused a large amount of erosion. The sediment mass was dumped into the rivers choking them and making them more inefficient.
74
What is the rural population density in Bangladesh?
1000 persons per square kilometre.
75
How many people were hit by the typhoid and hepatitis outbreak in Bangladesh?
70 000
76
What heightened the lack of sanitation post Bangladesh flood?
Poverty meant lack of access to adequate sanitation. (1 in 8 wells contaminated).
77
What threatens Bangladesh long term?
Sea level rise makes the country potentially inhabitable in the future.
78
(Bangladesh) short term government response:
emergency relief provided to victims
79
(Bangladesh) long term government response:
Hundreds of new tube wells were drilled. And millions of water purification tablets handed out.
80
(Bangladesh)International short term response:
UNICEF sent out essential drugs and bags of saline water to assist in combating dehydration.
81
(Bangladesh) Long term international response:
assistance targeting flood prone areas and building defence.
82
What is an example of curfews in disease prevention?
In Sierra Leone in 2015 in an effort to contain the spread of the Ebola virus
83
What are three diseases that depend on a warm humid climate?
Malaria, dengue fever, yellow fever
84
Why might disease spread due to precipitation be seasonal?
Because rainy seasons may vary seasonally and spatially.
85
How does precipitation have an effect on the spread of disease?
Creates stagnant water sources for vector development. Allows for development of water borne diseases
86
How does temperature have an effect on the spread of disease?
Viral replication and vector development relies heavily on temperature.
87
How does relief have an effect on spread of disease?
High altitudes tend to have Lower temperatures which a large number of zoonotic diseases cannot survive as the organisms only function and reproduce at certain temperatures
88
Dengue is a widespread disease in ....
the tropics
89
annually dengue fever infects...
400 million people
90
How does climate control dengue fever epidemiology?
mosquitoes thrive in warm, humid conditions, which in turn favours the outbreak of dengue
91
What conditions trigger dengue outbreaks?
sustained 32 degree temp and humidity above 95% (tends to occur only in summer months)
92
What is an example of seasonal variation in disease outbreaks?
in temperate regions in the northern hemisphere epidemics of influenza peak in the winter months as the transmission of the virus is most efficient at lower temperatures
93
What are main affects of climate change on spread of infectious diseases?
- increases temp
-increases rainfall
-increases humidity
-overall all of these have stimulated transmission of vector borne diseases
94
What is an example of the effect of climate change on the spread of disease?
Lyme disease caused by ticks. ticks thrive much more in warmer conditions
95
How is Sleeping Sickness an effect of climate change?
Disease is transmitted to humans via tsetse fly. outbreaks only occur when temp range is between 20 and 26. it means that in the future the disease is likely to spread to Southern Africa. will affect 77 million more people by 2090
96
When does the probability of zoonotic diseases being transmitted to humans increase?
- movement of wild animals is unrestricted by physical barriers
-controls on the movement of diseased domestic animals within countries are ineffective
- urbanisation creates suitable habitats for animals such as foxes and racoons
-limited control in urban areas of feral cats and dogs
-poor hygiene and sanitation (contaminated water sources)
97
what model is used for the link between disease and level of development?
Oman's model
98
what are the four stages of Omran's model?
1. age of pestilence and famine
2. age of receding pandemics
3. age of chronic diseases
4. age of delayed degenerative diseases
99
Draw the mortality rate against epidemiological transition graph for Omran's model:
x shape. least developed on left, most developed on the right. communicable on bottom, life style of the top
100
Epidemiological transition:
a characteristic shift in disease pattern of a population as mortality falls during the demographic transition (a curve). Infectious diseases increase in prominence causing a gradual shift in the age pattern of mortality from younger to older ages.
101
Demographic transition model:
a change in the population dynamics of a country as it moves from high fertility and mortality rates to low fertility and mortality rates
102
what are the key factors of the age of pestilence and famine?
- pre industrial societies
- mortality is high and fluctuates
- life expectancy is low (poor sanitation and low standards of living, people are more vulnerable to disease)
-slow population growth
-most countries today have passed through this phase
103
What are the key factors of the age of receding pandemics?
-in industrial societies (many EDCs and LIDCs today)
- advances in medical tech, diet and living standards
-life expectancy rises above 50 years and death rates start to fall
- pop growth is sustained
- main cause of death shifts to degenerative diseases
104
What are the key factors in the age of chronic diseases?
- many emerging countries now entering this phase
- further improvements to medical technology, hygiene and living standards
-mortality related to infectious disease is rare
- reduced fertility
- life expectancy rises to 70
- degenerative diseases become main cause of mortality
105
What are ht key factors of the suggested fourth phase of Omran's model?
- medical advances delay onset of degenerative diseases
- older people have lower morbidity
- lack of physical activity and unhealthy eating have resulted in rise of lifestyle related diseases such as obesity
106
What are the risks of using Omran's model?
it is a generalisation, not all countries will follow this pattern at the same time and speed, some countries such as china are moving through it at an accelerated rate
107
What are the infant mortality rates per 1000 in Ethiopia, India and UK
stage 2 Ethiopia: 35
stage 3 India: 27
stage 4 UK: 4
108
What are the two main social links between development levels and disease diffusion?
- limited access to health related education
-poor diets lead to malnutrition and undernutrition which can weaken immune system and increase likelihood of vitamin deficiencies and increase vulnerability to infectious diseases
109
What is the main political factor linking development and spread of disease?
Type and structure of governments and their policies affects health of the poorest more than other groups. Every component of the government can have an indirect effect on population health
110
What are the three main physical factors linking development and disease?
-tropical and subtropical climates are an ideal breeding territory for disease vectors
- most of the world's poorest countries are located in tropics and subtropics where the climate and abundant rainfall promote infectious diseases
-climate change has led to an increase in temperature, rainfall and humidity, stimulating transmission of vector borne diseases
111
What are the three main economic links between development and disease?
-2 billion people globally lack regular access to existing drugs, rising to 50% in poorest parts of Africa and Asia.
-Poverty of state governments means insufficient suitable finance and lack of resources to increase scale of interventions can cause epidemics
-inadequate sanitation and poor housing tend to be a result of poor economy
112
In LIDCs, .............. cause a higher proportion of deaths and morbidity than..........
communicable, non communicable diseases
113
WHO estimated that ....... people did not have enough to eat in 2018
820 million
114
How can health and economic development spiral in two directions?
upwards: economic development supports better healthcare which in turn leads to higher productivity and economic growth
downwards: as poor health slows economic development, either there is less money for healthcare or money is diverted that should be spent on sustaining economic development
115
Why is there a higher proportion of deaths from non communicable diseases in Acs?
-successful reduction of communicable diseases as a result of government wealth
-high standards of living
-education and awareness
116
Non communicable diseases are an increasing problem in....
EDCs and LIDCs because of over nutrition and poor education
117
More than ....... of people living in Chile, Mexico and Ecuador are overweight or obese
2 thirds
118
What causes obesity?
-sedentary lifestyle and job
-diets containing large amounts of sugar and calories
-food marketing
-poor education
119
What causes type 2 diabetes?
- raised blood sugar levels
-large amounts of sugar and calories
-lack of exercise
-tobacco use
120
What causes CVD?
-build up of fatty material in arteries
-high blood pressure
-smoking
-can cause heart attacks and strokes
121
What are the five key causes of CDs in LIDCs?
poverty, inadequate nutrition, poor living conditions, poor governance, lack of resources
122
What are the four key causes of NCDs in Acs and increasingly in EDCs and LIDCs
prolonged life expectancy, sedentary lifestyle, malnutrition, over nutrition
123
My most measurements, what is the most polluted area in the world?
Delhi
124
What is Delhi's PM2.5 level?
153
125
What can pollution cause?
respiratory problems such as asthma, bronchitis, lung and heart disease and cancer
126
By how much has cancer risk in Delhi increased?
70% in last 20 years
127
How much has air pollution in Delhi reduced the life expectancy by?
3 years
128
What is air pollution in Delhi due to?
due to emission on NO2 and SO2 and ozone, principally by motor vehicles, coal burning power stations and factories
129
What are the temporal variations in air pollution in Delhi?
-growing population
-industrialisation (80% of factories are developed unplanned and unapproved)
-seasonally during October to December it drops to very poor with levels above 500 due to vehicle pollution and cold weather
130
What are three solutions to air pollution in India?
-Chimneys of brick kilns have been retro fitted to reduce smoke emissions
-14 Indian cities are currently building rapid transit metro systems
-2016 odd even system reduced commuters
131
What are three global solutions to air pollution?
-In 2012, 37 countries and the EU states agreed targets to cut out CO2 emissions by 19% of 1990 levels by 2020
-EU states have set out even more ambitious targets since
132
Mitigation:
an action which is taken to lessen the impact of natural hazards on people, economy and society
133
Response:
reaction to something after it has started
134
direct strategies:
actions to combat the disease source
135
Indirect strategies:
actions often involving mitigation of vulnerability
136
example of direct Strat:
eradication of mosquitoes via spraying
137
example of indirect Strat:
early diagnosis and treatment
138
What is the case study for how effectively communicable diseases are dealt with?
Ethiopia, Malaria
139
Malaria is caused by...
plasmodium parasites
140
In Ethiopia, malaria thrives in the....
humid lowlands but is absent in highland regions
141
What are four factors affecting Malaria transmission in Ethiopia?
-location for anopheles mosquitoes to lay eggs, each species has their own preference (i.e. stagnant water in hoof prints)
-transmission is more intense in locations were mosquito lifespan is longer
-transmission depends on climatic conditions which can vary seasonally
-human immunity levels - why most cases occur in children as they have much lower immunity
142
Name three direct strategies to Malaria mitigation:
insecticide treated mosquito nets, indoor residual spraying, anti malarial drugs
143
What are three indirect strategies to malaria mitigation?
education, early diagnosis after infection, surveillance
144
What are four problems/obstacles to mitigating malaria in Ethiopia?
resistance to insecticides, resistance to antimalarial drugs, lack of funding, misuse of nets
145
What factor increases susceptibility to malaria in ethiopia?
Poverty which causes under nutrition
146
What is President's Malaria Initiative?
health extension workers at local community level raise awareness. government organised scheme. vehicles used to transport nets and sprays to community.
147
...... of Ethiopians do not have access to basic healthcare services
40%
148
Who is hit the hardest by malaria?
children and women
149
Between 2008 and 2013, Ethiopia received grants of......... a year for malaria control
20-43 million dollars
150
what four agencies are assisting Ethiopia in their fight against malaria?
UNICEF, WB, WHO and NGOs
151
What are two positives that have come form Ethiopia's mitigation of malaria?
death rates from malaria halved between 2000 and 2010
since 2003 there have been no major epidemics despite usual 5-8 year rotation
in Amhara, one of the worst hit areas had a drop of prevalence form 4.6 to 0.8%
152
What are four negative that have come from the strategies to control malaria in the
still not enough nets, DDT being sprayed is poisonous and has side effects, almost 45 million people still remain at risk of malaria, ACT drug is still very expensive
153
Globally one in .... deaths is due to cancer
6
154
What are the two most common cancers?
breast and lung
155
what percentage of cancers can be prevented by avoiding risk factors?
42%
156
Cancer arises from...
transformation of m=normal cells into abnormal tumour cells which have uncontrolled growth and can invade and destroy surrounding healthy tissue
157
what three external agents that can contribute to causes of cancer?
UV and physical carcinogens, tobacco and chemical carcinogens, viruses and biological carcinogens
158
.... percent of cancer victims are older than 50
87
159
In the UK, in 2017 what percentage of deaths was due to cancer?
27%
160
What are the long term trends in cancer incidence and prevalence?
I: gradual increase over last 40 years, it has doubled
M: very gradual decrease
161
Why might mortality have decreased but incidence of cancer increased?
because screening has meant people can have a n early diagnosis and therefore a prompt treatment
162
What two types are the main cancers with increasing prevalence?
liver due to alcohol consumption and melanoma due to sun bed culture
163
For males what is the most diagnosed type of cancer?
prostate
164
why has there been a temporal shift in cancer diagnosis due to covid
incidence was lower as there was no screening during the lockdown periods which has meant that many patients are still too scared to go in. estimate 24,000 cases have gone undiagnosed because of it
165
what is the backlog on breast cancer screening due to covid?
2.1 million people nationwide waiting to undergo screening
166
Where in UK is the highest prevalence of cancer and why?
north and in major cities such as London due do societal and environmental factors
167
Generally speaking do British white have lower or higher incidence of cancer than British Indian? why?
higher, due to different cultures and genetic makeup
