Disease Dilemmas (DD) Flashcards
Disease:
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.
Infectious:
Spread by pathogenic microorganisms such as bacteria, viruses or parasites.
Non-Infectious:
Diseases that cannot be spread by pathogenic microorganisms (usually due to diet and lifestyle)
Communicable:
Infectious diseases which spread from host to host.
What is animal to animal/animal to person spreading called?
Zoonotic
Non-Communicable:
A non-infectious, non-contagious disease that is not transmissible among people or other hosts (e.g. cancer).
Contagious:
A class of infectious disease that is easily spread by direct or indirect contact between people.
Epidemic:
Disease outbreaks that spread quickly through the population of a geographical area, affecting many people at the same time.
Endemic:
Disease that exists permanently in geographical area or specific human group.
Pandemic:
Epidemic outbreaks that spread worldwide.
Prevalence:
Proportion of cases in a population at a given time
Incidence:
Occurrence of new cases.
Mortality:
Incidence of death
Morbidity:
Refers to the state of being diseased.
Epidemiology:
Branch of medicine concerned with incidence, distribution and possible control of diseases.
In how many countries is malaria an endemic disease?
95
How does malaria come about?
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.
Where is the greatest amount of malaria (percentage and country)
23% of malaria cases can be found in Nigeria
How many worldwide cases of malaria are there?
229 million
Why is malaria a leading cause of child mortality?
Because children under five are most vulnerable.
What climate is needed for malaria and why?
Warm and humid environments (27 degrees) else larvae cannot complete its cycle as it will not be optimum temperature.
Why is high rainfall crucial to malaria?
Large rainfall near the equator results in stagnant water for the mosquitos to lay their eggs in.
What are two climates in which mosquitos cannot live?
High altitude (low temp) and dry desert (no water).
What has been implemented to lower the risk of malaria (short answer).
Nets and pesticides.
What does HIV stand for?
Human Immunodeficiency Virus
What are three features of HIV?
Communicable, infectious, contagious
How does transmission of HIV occur?
Through bodily fluids
In South Africa, what percentage of the population lives with HIV?
13%
What two countries have the largest amount of HIV cases?
Zambia and South Africa
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.
Why has their been progress in LIDCs regarding AIDS/HIV (short answer)?
Self testing and anti retroviral drugs (ARTs)
What are four features of TB?
Contagious, infectious, communicable, epidemic.
How is TB spread?
Bacterial infection spread through the air person to person.
How many people died of TB in 2019?
1.4 million
What percentage of TB deaths were in EDCs and LIDCs?
95%
What is Diabetes?
A non-communicable disease caused by the deficiency of insulin.
What can diabetes lead to?
Heart, blood vessel, eye and kidney damage.
How many diabetes cases in Western Pacific?
132 Million
What is temporally expected of diabetes?
That there will be a massive increase in cases by 2040.
What is CVD?
Cardiovascular Disease
Globally how many deaths does CVD account for?
17 million deaths per year
Why are ageing populations at risk of CVD?
Because incidence rises steeply with age.
Why is poverty linked with CVD
Disadvantaged people are at greater risk of being exposed to unhealthy dietary practices.
Disease diffusion:
The process by which a disease spreads from its geographical source.
What are the four types of disease diffusion?
expansion, diffusion, hierarchal, relocation
Expansion:
Disease spreads from one place to another forming new areas of prevalence. It also remains in the area of the outbreak.
Relocation:
The diseases moves to new areas but does not stay in the area of the outbreak.
Contagious (Diseases Diffusion):
The spread of disease through direct contact with a carrier. It is strongly influenced by the factor of distance.
Hierarchal:
A disease spreads through an ordered sequence of places, usually from the largest centres with the highest connectivity, to more isolated centres.
What model is used for disease diffusion?
Hagerstrand
What are the four stages of the hagerstrand model?
Primary, diffusion, condensing, saturation.
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.
What is the Primary stage? (hagerstand)
Strong contrast in disease incidence in the are of outbreak and more remote areas.
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.
What is the condensing stage? (hagerstrand)
the number of new cases is equal in all locations, irrespective of distance from the source
What is the saturation stage? (hagerstrand)
Diffusion accelerates as the incidence of the disease reaches its peak.
What three important concepts does the Hagerstrand model highlight?
Neighbourhood effect, S shaped curve and barriers to disease.
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.
What is the S shaped curve concept?
The number of people infected by an epidemic approximates an S shaped curve.
What is the hagerstrand barriers to disease concepts?
Progression of disease may be interrupted by physical barriers.
What are 5 physical barriers to disease?
distance, high mountain ranges, large maritime areas, extensive areas of aridity and climate.
What are 6 socio-economic barriers to disease diffusion?
quarantines, vaccination programmes, face masks, cancelling public events, health education, medical health checks at airports.
What are four global patterns that impact disease patterns?
Precipitation, relief, temperature and water sources.
Natural hazard:
When a natural process puts human lives, infrastructure, or economic interest at risk.
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.
What is the case study linked to natural hazards and disease?
Bangladesh flooding in August 2007 causing typhoid and hepatitis.