1. Malaria control and prevention

2. Controlling malaria. When trying to control malaria there are three main approaches that you can take: Control against the adult mosquito (stopping people from being bitten by them) Control against the eggs and larve (to stop the adult mosquito from being born) Control against the plasmodium (by treating people)

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

4. Insecticide sprays This is when the chemical DDT is sprayed on the walls of homes. This is the most widely used method and it is recommended by the WHO. Sprays must be applied repeatedly for long term effectiveness.

5. Insecticide sprays DDT is unfortunately poisonous to humans. It can get into water supplies and can be passed on to young children through breast milk. Even though it is cheap very poor villages can not afford to pay for this treatment. MOST IMPORTANTLY: The mosquitoes can quickly become immune to the chemical making the spraying worthless.

6. 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.

7. Effectiveness of DDT There is no denying that DDT can be effective as the graph on the last slide highlighted. Also there was around a 60% drop in cases of malaria when D.D.T. was introduced to Ecuador in 1993 and a 90% increase when it was withdrawn from Bolivia in 1993. Overall it is a good method but can’t halt the spread of malaria entirely.

8. A simple mosquito net.

9. Mosquito net Mosquito nets are a great way to combat the spread of malaria. First of all they physically stop the mosquito from landing on you when you sleep and feeding.

10. Mosquito net The women in this picture are treating the mosquito net with insecticide. The most common chemical to use is Permethrin, which is harmless to humans, but deadly to mosquitoes.

11. Mosquito net This is a very popular way of combating malaria with the charity “Roll back malaria” It can be extremely effective but it is up to three times as expensive as DDT. Several African countries are endorsing this method and removing tax on the nets.

12. Genetic engineering Labs produce sterile male mosquitoes so that the breed die out. This is very time consuming and it can not be replicated on a large scale.

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

14. PHYSICAL CONTROL 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.

15. Draining/flooding stagnant water In theory this is a good idea. However the scale on which it would have to be done is too great. Pools of water would have to be drained once every 5-7 days as the mosquito breading period is 8-10 days. Mosquitoes only need a pool of water the size of a footprint to breed so it is unlikely that all pools of water would be drained. Also LEDC can’t afford to empty their reservoirs on a regular basis.

16. This is very similar to the spraying of DDT but on to the breeding grounds. It suffers from the same success’ and failures of DDT as well as the fact that it is unlikely that all pools of water will be found. Spraying with Lavicides

17. BIOLOGICAL CONTROL Adding larvae-eating fish, such as the Muddy Loach, to padi fields and pools, can clear them of larvae within a day. Can you think of any other benefits of this method?

18. Adding larvae eating fish Although it is initially expensive it can provide a source of food for local people. Unfortunately it can endanger local wildlife species.

19. A number of techniques can be used to drown the larvae

20. Drowning Larvae Adding mustard seed to the water will drag the larvae down. Spraying the water with egg whites clogs up the breathing system of the larvae. Spraying oil on the water also causes them to suffocate. After all the problems with effectiveness that we have looked at what do you think the limitations of these methods could be?

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

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

23. 3. AGAINST THE PLASMODIUM… 1.Quinine: Originally extracted from the bark of the South American Cinchona (Fever Tree), it was for a long time the main anti malarial drug. 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.

24. AGAINST THE PLASMODIUM… 2. Chloroquine: Now the most common anti malarial drug, but, like Quinine, becoming ineffective as the Plasmodium mutates and becomes immune to it.

26. ..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.

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

28. New discovery A recent discovery has been made in a vaccine that claims to half the chances of a human contracting malaria. There is no proven test yet but initial findings are positive. The WHO has admitted the battle against malaria is currently being lost and the must do more to stop it. It is clear that the problems will not stop any time soon.