HIGHER / INTERMEDIATE GEOGRAPHY DEVELOPMENT AND HEALTH

1. HIGHER / INTERMEDIATE GEOGRAPHY DEVELOPMENT AND HEALTH MALARIA

2. Choices …to run through the whole show, simply left-click your mouse button. To jump to a particular section, click on the appropriate button below. To return to this page, click 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 - 2.3 billion people - about 40% of the world’s 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.

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. The link between the disease and the Anopheles Mosquito was first made by Ronald Ross, a Scottish army doctor, working in India. 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.

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. Back to CHOICES An adult emerges, the males to look for plant nectar, the females for blood.

19. 2. THE EFFECTS

21. Several days of headaches and vague, flu-like pains of the body… 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 coldstage – 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. Back to CHOICES 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.

32. 3. THE RISK FACTORS

33. 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. MALARIA - RISK FACTORS - 1

34. 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.

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

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

49. 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. Planting Eucalyptus trees to absorb excess water from the soil helps drain breeding sites. PHYSICAL CONTROL

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.