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Health
Malaria
Background
The name comes from the
Italian mal (bad) and aria (air)
– it was originally thought the
disease was spread by the
damp air from swamps.
The link between the disease and
the Anopheles Mosquito was first
made by Ronald Ross, a Scottish
army doctor, working in India.
When the Anopheles Mosquito “bites”, it
actually sinks a long, thin mouth part, the
proboscis, into the skin.
The mosquito then pumps saliva under the skin, to
stop the blood clotting – so that it can drink
uninterrupted! In the saliva is the main culprit, the
Plasmodium, a single-cell blood parasite.
Global Distribution of Malaria
It is predominantly a
disease of the Tropics.
Malaria is a disease which is endemic in many
countries – this means it is always present.
MALARIA TODAY…
Global population at risk: 2.3 billion people (about
40% of the world’s population)
Number infected: 500-600 million people
Global mortality: between 4000 and 8000 deaths
each day
In the time it takes to say the word malaria, ten
people (seven of them children) will have caught it.
Every 30 seconds, a child dies of malaria.
Task
In groups, collect one Higher Paper 2 past
paper from 2008, 2007, 2006 & 2005.
Development & Health is always Q6.
Come up with a list of what you will need to
know about Malaria for the exam (5 mins).
Summarise the list into five main ‘objectives’ for
what you need to know about Malaria.
Objectives – Please Copy
Human causes/risk factors of Malaria
Physical (environmental) causes of Malaria
Methods/strategies of control
Effectiveness of strategies
Benefits to a country of controlling Malaria
Task
Take detailed notes on Physical Causes and
Human causes.
Use all the relevant textbooks/photocopies.
Tip: remember to include numbers/figures
where possible.
Human Causes of Malaria
Human blood supply.
Areas of stagnant water where mosquitoes
can breed e.g. tank wells, irrigation channels
etc.
Mosquitoes will breed where you have poor
drainage, irrigation or poor sanitation.
Lack of health care facilities.
Migrants moving into malarial areas - clearing
land, looking for work, refugees etc.
Poor housing, like this shanty, offers little protection.
Physical Causes of Malaria
Moist hot climate (15°C - 40°C)
Areas of shade where mosquitoes can digest
meal.
Presence of female anopheles mosquitoes.
Ideal breeding grounds for mosquitoes – still, shallow water.
Mosquitoes will breed in small puddles, even in animal
hoof prints, empty cans and bomb craters.
A jar containing mosquito larvae.
A high risk area – people, vegetation cover
and stagnant water during the wet season.
Solutions & Effectiveness
Make detailed notes on solutions AND their
effectiveness under 2 categories:
Prevention
Treating Sufferers
Ways to prevent Malaria
Insecticides can be
sprayed in homes to kill
mosquitoes e.g.
Malathion.
Effective but expensive
as it is petroleum based.
Also smells bad and
stains walls yellow.
Ways to prevent Malaria
Mustard Seeds are put
on water surfaces as
they become sticky
when wet. They drag
mosquito eggs under
water and drown them.
This is difficult to
maintain & seems
wasteful.
Ways to prevent Malaria
Spraying Egg Whites also kills larvae on
stagnant water as it suffocates them by
clogging up their breathing tubes.
This also seems wasteful.
Ways to prevent Malaria
Bti bacteria in coconuts is eaten by larvae and
destroys their stomach lining. Coconuts are left to
ferment for a few days, broken open & thrown into
ponds.
Effective
1. 2/3 coconuts ‘control’ a pond for 45 days
2. Cheap to produce & plentiful
3. Bacteria is not harmful to humans or animals
Ways to prevent Malaria
Larvae-eating fish introduced to paddy fields.
These are effective PLUS a useful source of
protein to be added to peoples’ diet.
Ways to prevent Malaria
Drainage of swamps & irrigation channels.
This is effective but not always practical in
tropical places as it rains a lot. Also very
expensive.
Ways to prevent Malaria
Release water from dams to drown larvae.
This is successful but has to be done every
7-10 days to fit in with breeding cycle.
Ways to prevent Malaria
Planting Eucalyptus trees to absorb excess water
from the soil helps drain breeding sites.
Education “Prevention easier than Cure”
Use insect repellent
Cover exposed skin at dusk (when mosquito
most active)
Sleep under a mosquito net sprayed with
insecticide
This is thought to be most effective treatment
(30% of child deaths could be avoided) &
cheap to implement
We can also treat sufferers:
Chloroquine (drug)
Easy to use and cheap but
mosquitoes are becoming
resistant to it.
Larium (drug)
Powerful and effective but can have harmful
side-effects.
Vaccines
This would be the most effective treatment
(easier to give out than a course of drugs and
offers lasting protection)…
However, a successful and widely available
one has not been invented yet. Trials still
going on in Gambia and Columbia.
Quinghaosu (drug)
Plant extract which has been used as a
traditional cure in China for many years.
It can be put into pill form making it easy to
take and distribute.
This is a possible future solution, especially
considering China’s improved relationship
with the West.
No ONE solution has been found
A mix of strategies is most successful.
WHO “Roll Back Malaria” programme (global
campaign aimed at halving number of Malaria
cases by 2010).
Bill Gates Foundation donated £105 million to
help research a vaccine and new drugs to
fight this disease.
KEY REVISION POINTS
Anopheles Mosquito
Plasmodium
Humid climate: 16-40ºC, abundant rainfall
Vegetation for shade
Areas of still or stagnant water
Lost education through bouts of illness
Lost productivity by adults, especially at planting and harvest
time – less food, lower income
Huge amount spent on trying to prevent or control malaria
Negative impact on foreign investment and tourism
KEY REVISION POINTS
Malathion
Genetic engineering – sterile male mosquitoes
ITNs – Insecticide Treated Bed nets
Draining and flushing breeding sites
Oil, egg whites and mustard seeds
Bti, Fish (Muddy Loach), Eucalyptus trees
Chloroquine, Artemisia
No effective vaccines yet - several on trial
World Health Organisation campaign – Roll Back
Malaria
Benefits to ELDCs of eradicating Malaria
Less money spent on medicine, drugs, insecticides, doctors,
drainage etc.
Saved money available to be spent in other areas of the country’s
economy.
There will be healthier workforce which will speed up development.
EMDCs more likely to invest in ELDCs that have eradicated malaria.
Malaria-free countries can encourage tourism which will benefit the
economy.
Longer life expectancy.
Reduction in national debt.
Lower infant mortality means birth rate will fall & population growth
will slow down.