1. Malaria Caused by Plasmodium spp. –Protist Female Anopheles mosquito feed on human blood and acts as a ‘vector’ for the parasite –Transfers it between humans May also be transferred by: –Blood transfusions –Unsterile needles –Across the placenta from mother to a foetus

2. Plasmodium life cycle Mosquito takes up some of the parasite’s gametes from an infected person Pass into the next human with anti-coagulant in saliva of mosquito Enters red blood cells of human Multiplies in human and in mosquito

3. Life Cycle Plasmodium

4. Infected Red Blood Cells

5. Features of Malaria

6. Occurence

7. Immunity May become immune if continually reinfected –Have to survive first five years of infection Epidemics where malaria is not endemic are very dangerous –And where outbreaks after the rainy season

8. Controlling Malaria 1.Reduce number of mosquitoes 2.Avoid being bitten 3.Drugs to prevent the parasite infecting people

9. Kill Mosquitoes Spread oil on water which mosquitoes breed in –Prevents larvae from getting oxygen from the surface Drain marshes Add fish which eat mosquito larvae to ponds etc. Spray with bacterium which kills mosquito larvae

10. Avoid being bitten Nets Insect repellent Soak nets in insecticide Cover skin at dusk Sleep with a dog or a pig!

11. Drugs Treat infected people and as prophylactic (preventative) Quinine Chloroquine –Prevents parasite spreading by inhibiting protein synthesis Plasmodium may develop resistance –Eg widespread chloroquine resistance –Use Mefloquine instead, but: Expensive & side effects: dizziness, vomiting, disturbed sleep

12. At Risk Visitors to countries Misdiagnosed in other countries (‘flu) Immigrants who visit relatives –Immunity is lost

13. Eradication Attempt 1950’s, World Health Organisation Unsuccessful, because: –Resistance by Plasmodium –Resistance by mosquitoes (eg to DDT) Immunity lost and resulted in deaths when the disease returned Expensive Insecticides killed wasps which ate caterpillars which eat thatched roofs Programme did not involve indigenous people

14. Concern Increase in resistance of Plasmodium Increase in worst species, P. falciparum Climate change favours outbreaks Increased migration (due to wars) No vaccine available One of world’s biggest health threats

15. Progress…. Improve diagnosis eg ‘dipstick’ test Supply effective drugs –Eg Genome sequencing of plasmodium to find vaccine Use drug combos to reduce resistance Prevent transmission