Malaria What do I need to know? The physical and human causes of malaria The impact of malaria on individuals, communities and countries Methods of controlling malaria How effective these methods are

Distribution of Malaria

Malaria Distribution and Resistance

Facts m clinical cases p.a. worldwide Up to 3m deaths worldwide p.a. 90% of all deaths are in sub-Saharan Africa  A child dies of malaria every 25 seconds  Malaria is on the increase for the first time in 20 years due to drug resistance

Eggs hatch Mosquito lays eggs in stagnant water Parasites attack the liver, mature and reproduce Mosquito bites another person and transfers the parasite Parasites are released into the bloodstream Malaria parasites develop within the mosquito Female sucks blood from an infected person becoming a vector or carrier Mosquito must feed on blood to survive

Causes Female anopheles mosquito Stagnant water – puddles Moderate to high rainfall Temperatures o c High population density Shade for mosquito to rest Altitude below 3000m Humidity over 60%

Human Causes Stagnant water – padi fields, bomb craters, irrigation canals Shade created by urbanisation Increased travel, trade and tourism

Impact on individuals Fever, shivering, anaemia, enlarged spleen, can be fatal especially if immune system is weakened by malnutrition or other illness. Lose 8-10 days work per attack Income 60% lower than non-malarial areas Risk of infection highest in rainy season – coinciding with agricultural peak

Impact on communities More likely to focus on subsistence cropping which is less risky than cash cropping Chronic absenteeism in school children

Impact on countries Loss of income due to illness Growth of GDP is lowered by 1-3% per year Accounts for 30-50% of all hospital admissions Costs up to 40% of public health expenditure

Controlling Malaria MethodAdvantagesDisadvantages Drain breeding sites by filling depressions and planting eucalyptus trees Removes the breeding sites Impossible to implement as the mosquito can breed in a muddy footprint Canals need to be flushed every 5-7 days to disrupt breeding cycle – clean water is too valuable

MethodAdvantagesDisadvantages Introduce natural enemies Spores Carp – eat larvae Mustard seeds – sticky – drown larvae Egg white – suffocate larvae Parasitic wasps – eat larvae Natural Carp add protein to diet Carp are self sustaining No risk to human health Wasteful Expensive Risk to indigenous wildlife

DDTCheap Easy to apply effective Due to be banned in 2007 Damaging to environment Risk to human health Mosquitoes build up resistance MalathionLess risky than DDT Expensive Needs to be re- applied more often Unpleasant smell

Insecticide treated bed nets Lasts up to 1 year Reduced incidence in Tanzania by 35% 3x as expensive as DDT $4 per net, 25 cents for insecticide Some countries (Ethiopia) tax bed nets

Bti bacteria grown on coconuts – thrown into stagnant water Destroy stomach lining of larvae Cheap No risk to environment Coconuts are plentiful and often grow near stagnant water Last up to 45 days Need coconuts Only suitable for larger areas of water i.e. not puddles

Anti-malarial drugs ChloroquineCheap Easy to use Mosquitoes developed resistance LaruimMore powerfulSide effects Mosquitoes will be resistant in 10 years Malarone98% effective Few side effects expensive

Drugs continued Quinghaosu – developed from chinese herbal medicine or Artemissinin (commercial name) Fast acting Mosquitoes NOT becoming resistant so far Easy to take Very expensive

Vaccine Currently being researched Bill & Melinda Gates Foundation None currently available – 10 years away Genetic engineering Aim to make mosquito unable to carry parasite Very expensive Difficult to apply to all mosquitoes Primary Health Care Affordable Focus on education removing breeding sites using bed nets Covering skin at dusk Relies on public finding Usually small scale projects