1. 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

3. 1. THE CAUSE

4. MALARIA TODAY…
Global population at risk billion people - about 40% of the world’s population
Number infected million people
Global annual mortality 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.

5. 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.

6. 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.

7. It is predominantly a disease of the Tropics.
Malaria is a disease which is endemic in many countries – this means it is always present.

8. …with global warming, however, malaria may be closer than you think…

9. 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.

10. 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.

11. PLASMODIUM – 4 MAIN SPECIES
Plasmodium ovale
Plasmodium vivax
Plasmodium malariae
Plasmodium Falciparum – the most deadly.

12. If the mosquito is carrying the Plasmodium, then it will transfer it to the victim’s 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.

15. Mosquito larvae hang from the surface tension of the water, breathing through their siphon tube.

16. A jar containing mosquito larvae.

17. Pupae ready to hatch into adult mosquitoes

18. An adult emerges, the males to look for plant nectar, the females for blood.
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19. 2. THE EFFECTS

21. Several days of headaches and vague, flu-like pains of the body…
INFECTION
Several days of headaches and vague, flu-like pains of the body…
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…

22. Millions of red blood cells are destroyed in an attack of malaria.

23. A remarkable close-up of destroyed red blood cells.

24. 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.

25. 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.

26. A young victim of Falciparum Malaria

27. …and another

28. Without rapid medical help, many of these children will die: currently one every 30 seconds or less.

29. Adult victims will have repeated attacks for many years, unless treated. When ill, they cannot work.

30. 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.

31. Tourists and foreign investors avoid malaria ridden areas.
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.
Africa’s 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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32. 3. THE RISK FACTORS

33. 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 16°C and 40°C 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.

34. MALARIA RISK FACTORS - 2 HUMAN
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.

35. Ideal breeding grounds for mosquitoes – still, shallow water.

36. Mosquito larvae at the edge of a pool.

37. Mosquitoes will breed in small puddles, even in animal hoof prints, empty cans and bomb craters.

38. A high risk area – people, vegetation cover and standing water during the wet season.

39. 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.

40. Poor housing, like this shanty, offers little protection.

41. 4. THE SOLUTIONS

42. 3 Areas of Control Against the adult mosquito;
Against the eggs and larvae;
Against the Plasmodium, by treating victims.

43. INSECTICIDE TREATED BED NETS (VERY LIMITED SUCCESS)
1. AGAINST ADULT MOSQUITOES
INSECTICIDE SPRAYS
(SUCCESSFUL…BUT)
INSECTICIDE TREATED BED NETS
(VERY SUCCESSFUL)
GENETIC ENGINEERING
(VERY LIMITED SUCCESS)
STERILE MALES
DDT
MALATHION
KILLER MALES

44. 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.

45. The effect of stopping the use of DDT in Sri Lanka (Ceylon)
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.

46. A simple mosquito net may mean the difference between life and death…

47. …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.

48. 2. AGAINST EGGS AND LARVAE
PHYSICAL
CHEMICAL
BIOLOGICAL
SPRAYING WITH LARVICIDES
ADDING OIL, EGG WHITES OR MUSTARD SEEDS
DRAINING BREEDING SITES
FLUSHING BREEDING SITES
ADDING FISH TO PONDS AND PADI FIELDS
PLANTING EUCALYPTUS TREES
ADDING Bti IN COCONUTS

49. PHYSICAL CONTROL
Planting Eucalyptus trees to absorb excess water from the soil helps drain breeding sites.
Draining breeding places: because mosquitoes need so little water in which to lay their eggs, it can be virtually impossible to find and drain them all.
Flushing out breeding sites by weekly release of water can drown the larvae, but can only be done in suitable areas and where there is surplus water.

50. BIOLOGICAL CONTROL
Adding larvae-eating fish, such as the Muddy Loach, to padi fields and pools, can clear them of larvae within a day.

51. 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.
The incubation stage
Adding to pools
Spraying Bti from a boat

52. You can even buy Bti over the counter in the U.S.
BIOLOGICAL CONTROL - Bti
You can even buy Bti over the counter in the U.S.

53. 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.
Quinine: Originally extracted from the bark of the South American Cinchona (Fever Tree), it was for a long time the main anti malarial drug, but the parasite has become largely immune.

54. 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.

56. ..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.

57. VACCINATION
At the moment, there is no effective vaccine against malaria, although scientists all over the world are trying to develop one.

58. 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.

59. 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.

60. 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 Plasmodium’s ability to develop resistance to drugs.

61. Plasmodium (e.g. Plasmodium Falciparum);
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.

62. 5. KEY REVISION POINTS 1-3 million deaths each year, mostly children;
(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 Africa’s GDP; up to 25% of family income; huge burden on health services;
Negative impact on foreign investment and tourism.

63. 5. KEY REVISION POINTS DDT, Malathion;
(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.

64. Exam Advice
Practice this topic using past papers – the questions don’t 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 don’t 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.

65. 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
…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…