HIGHER GEOGRAPHY DEVELOPMENT AND HEALTH

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HIGHER GEOGRAPHY DEVELOPMENT AND HEALTH
MALARIA A Water-Related Disease
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1. THE CAUSE
2. THE EFFECTS
3. THE RISK FACTORS
4. THE SOLUTIONS
5. KEY REVISION POINTS
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1. THE CAUSE
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MALARIA TODAY

• Global population at risk - 2.3 billion people -
  about 40 of the worlds population
• Number infected - 500 - 600 million people
• Global annual mortality - 1.5 - 3 million
  deaths, or between 4000 and 8000 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.

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After dropping steeply between 1930 and 1970,
malaria is now making a real comeback, especially
in Africa, south of the Sahara, where 90 of all
deaths occur.
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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.
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It is predominantly a disease of the Tropics.
Malaria is a disease which is endemic in many
countries this means it is always present.
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with global warming, however, malaria may be
closer than you think
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INFECTION

• You can catch Malaria from blood transfusions,
• or infected needles,
• or intra placentally i.e from a mother to the
  baby in her womb.
• But by far the most common way is by being bitten
  by the female Anopheles Mosquito.

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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.
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PLASMODIUM 4 MAIN SPECIES

• Plasmodium ovale
• Plasmodium vivax
• Plasmodium malariae
• Plasmodium Falciparum the most deadly.

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If the mosquito is carrying the Plasmodium, then
it will transfer it to the victims bloodstream
in its saliva.
If the person is infected, then they will
transfer the Plasmodium into the mosquito, which
can then fly off and infect someone else.
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Mosquito larvae hang from the surface tension of
the water, breathing through their siphon tube.
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A jar containing mosquito larvae.
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Pupae ready to hatch into adult mosquitoes
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An adult emerges, the males to look for plant
nectar, the females for blood.
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2. THE EFFECTS
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INFECTION
Sweating stage patient soaked in sweat, but
begins to feel better after 2-3 hours
Several days of weakness and slow recovery
Sudden onset of cold stage patient shivers
violently and turns blue with cold, even though
his actual temperature is rising. Lasts about one
hour
Hot stage high temperature, headache, sickness
and dizziness. Lasts several hours
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Millions of red blood cells are destroyed in an
attack of malaria.
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Falciparum malaria - blood vessels to the brain
are blocked with dead red blood cells, starving
the brain of oxygen. Coma or death will follow
rapidly.
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Most at risk are the very young, who have not yet
developed any degree of natural immunity
along with pregnant women, whose immune system
is weakened.
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A young victim of Falciparum Malaria
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and another
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Without rapid medical help, many of these
children will die currently one every 30 seconds
or less.
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Adult victims will have repeated attacks for many
years, unless treated. When ill, they cannot work.
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THE COSTS

• The huge cost in terms of human suffering 1
  3 million deaths a year. Hundreds of millions
  ill.
• Massive impact on attendance of children at
  school. Education suffers.
• Large numbers unable to farm their land or
  collect in the harvest. The harvest coincides
  with the peak biting season for mosquitoes.

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THE COSTS

• Enormous financial cost to families to buy anti
  malarial medicines. In some cases 25 of their
  annual income. This is on top of paying
  preventative costs and lost income.
• Over 2 billion dollars spent on fighting the
  disease in Africa alone, money which could be
  spent on development.
• Africas GDP would be 100 billion greater if
  malaria had been wiped out thirty five years
  ago.
• Tourists and foreign investors avoid malaria
  ridden areas.

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3. THE RISK FACTORS
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MALARIA - RISK FACTORS - 1

• ENVIRONMENTAL
• The presence of Anopheles mosquitoes
• The presence of the plasmodium, in either the
  mosquitoes or human population.
• A warm, humid climate - temperatures between 16C
  and 40C and abundant rainfall.
• Areas of still / standing water. Only a tiny area
  of water is needed.
• Vegetation nearby to provide shade for the
  mosquito to hide during the day and digest the
  blood meal from the night before.

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MALARIA RISK FACTORS - 2HUMAN

• Poor water supply and sanitation.
• People nearby to provide reservoir of blood.
• People working in the fields and in irrigation
  systems, near or on lakes and reservoirs etc.
• Migrants moving into malarial areas - clearing
  land, looking for work, refugees etc.
• People (and mosquitoes!) travelling abroad,
  especially by air airport malaria.

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Ideal breeding grounds for mosquitoes still,
shallow water.
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Mosquito larvae at the edge of a pool.
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Mosquitoes will breed in small puddles, even in
animal hoof prints, empty cans and bomb craters.
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A high risk area people, vegetation cover and
standing water during the wet season.
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Collecting water, an essential fact of life for
millions of people, poses real risks of being
bitten. However, you cannot catch the disease by
drinking water containing larvae.
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Poor housing, like this shanty, offers little
protection.
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4. THE SOLUTIONS
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3 Areas of Control

• Against the adult mosquito
• Against the eggs and larvae
• Against the Plasmodium, by treating victims.

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1. AGAINST ADULT MOSQUITOES
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• Insecticide sprays are very efficient, but there
  are several drawbacks
• They are relatively expensive, often beyond the
  means of poor villages
• Sprays must be applied repeatedly for long-term
  effectiveness.
• They may contaminate water and crops.

4. Most importantly, mosquitoes can quickly
develop immunity to the spray.
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The effect of stopping the use of DDT in Sri
Lanka (Ceylon). Was the banning of DDT one of the
costliest mistakes of all time? One estimate
suggests that 50 million children have died of
malaria since the use of DDT was greatly reduced
in the 1960s.
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A simple mosquito net may mean the difference
between life and death
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even better if they are dipped in insecticide,
as in this Kenyan village. The normal chemical
used for ITNs (Insecticide Treated Nets) is
Permethrin, which is harmless to humans, but
deadly to mosquitoes. Several African countries
are trying to get more people to use these nets,
by removing tax on them, reducing their cost.
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2. AGAINST EGGS AND LARVAE
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PHYSICAL CONTROL
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BIOLOGICAL CONTROL
Adding larvae-eating fish, such as the Muddy
Loach, to padi fields and pools, can clear them
of larvae within a day.
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BIOLOGICAL CONTROL - Bti
The bacillus Bti (Bacillus Thuringiensis
Israelensis !!!) can be incubated in coconuts,
where it multiplies. The coconuts are then broken
open and thrown into pools, where the bacilli
are eaten by the mosquito larvae. They kill the
larvae by destroying its gut.
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BIOLOGICAL CONTROL - Bti
You can even buy Bti over the counter in the U.S.
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3. AGAINST THE PLASMODIUM
An ingredient of Tonic Water (check in the
supermarket), Quinine was often taken with Gin to
mask its bitter taste. However, you would need to
drink about 25 Gin and Tonics a day to get the
recommended dose.
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AGAINST THE PLASMODIUM
2. Chloroquine Became the most common anti
malarial drug, but, like Quinine, becoming
ineffective as the Plasmodium mutates and becomes
immune to it.
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..AGAINST THE PLASMODIUM
3. Artemisia (Wormwood) Used as an anti
malarial herbal remedy by the Chinese for
hundreds of years (known there as Qinghaoshu), it
was rediscovered during the Vietnam war and may
prove to be a major weapon in the fight against
malaria, as plasmodium do not seem to become
immune to it.
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VACCINATION
At the moment, there is no effective vaccine
against malaria, although scientists all over the
world are trying to develop one.
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The search goes on to try to find a vaccine the
Bill Gates Foundation recently donated more than
168 million towards malaria research, most of
that to find an effective vaccine available to
all.
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ROLL BACK MALARIA
Started in 1998, Roll Back Malaria is a global
programme aimed at halving the world's malaria
problem. It is a coordinated attempt involving
the WHO, UNICEF, the World Bank and many
governments and scientific and medical experts
across the world.
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SUCCESS OR FAILURE?

• At the moment there is no doubt that the battle
  against malaria is being lost.
• This is mainly due to the ability of mosquitoes
  to develop immunity to pesticide sprays
• and to the Plasmodiums ability to develop
  resistance to drugs.

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5. KEY REVISION POINTS
(i) THE PROBLEM

• Anopheles Mosquito
• Plasmodium (e.g. Plasmodium Falciparum)
• Humid climate 16-40ºC, abundant rainfall
• Vegetation for shade
• Areas of still or stagnant water
• Humans to act as blood reservoir.

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5. KEY REVISION POINTS
(ii) THE EFFECTS

• 1-3 million deaths each year, mostly children
• 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 - 2 Billion in Africa each year, maybe
  100 Billion damage to Africas GDP up to 25 of
  family income huge burden on health services
• Negative impact on foreign investment and tourism.

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5. KEY REVISION POINTS
(iii) THE SOLUTIONS

• DDT, Malathion
• Genetic engineering sterile male mosquitoes
• ITNs Insecticide Treated Bed nets
• Draining and flushing breeding sites
• Larvicide sprays to kill larvae
• Oil, egg whites and mustard seeds
• Bti, Fish (Muddy Loach), Eucalyptus trees
• Quinine, Chloroquine, Artemisia
• No effective vaccines yet - several on trial
• World Health Organisation campaign Roll Back
  Malaria.

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Exam Advice

• Practice this topic using past papers the
  questions dont vary that much from year to year.
• Concentrate more on the Risk Factors, Costs and
  the Solutions, less on the cycle of infection and
  medical symptoms of the disease.
• You must be able to comment on the effectiveness
  of your chosen solutions, but dont just say
  very effective for them all and hope to get
  marks the markers will be looking for detailed
  knowledge of the effectiveness of each solution
  you quote.
• Try to learn a few (four or five) solutions in
  detail and be able to quote names of pesticides,
  drugs, etc.

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Presentation produced by Robbie Livingstone,
Geography Department, Dunoon Grammar
School. Photographs and diagrams are used
without their authors permission and should not
be used for any commercial purposes. Any
constructive criticisms are welcome to
robert.livingstone_at_dunoongrammar.argyll-bute.sch.u
k this presentation will have taken about
half an hour to view. In that time about 60
people, most of them babies and young children
will have died from malaria