Post on 17-Dec-2015
Malaria Power point revision
With updates at the end
MALARIAA disease of the developing world
The Physical, Human, and Environmental factors which contribute to the spread of the disease
The physical factors
These are landscape, and climatic factors.
The physical factors
Malaria is found between 65degs N and 40degs S and below 3000m in altitude.
The physical factors
The anopheles mosquito needs humidity of 60% (not less than 25%), and mean monthly temperatures of over 18degs C (but above 32 degs C survival rates fall).
The physical factors
The female mosquito needs human blood as food to complete the breeding cycle, but can survive on animal blood which keeps the disease ever present.
The physical factors
They need still (stagnant) water surfaces as breeding areas, but these areas do not need to be large.
The physical factors
Water in a hoof print, an old tin can, a used tyre, all the way up to irrigation ditches, padi fields, and reservoirs offer potential breeding sites to anopheles mosquitoes.
The human factors
These are factors created by human activity.
The human factors
Nearby settlements to provide a ‘blood reservoir’ for female mosquitoes.
The human factors
Mosquito breeding is encouraged by bad sanitation and poor irrigation or drainage that leaves standing water uncovered – eg. tank wells, water barrels.
The human factors
Migration is now very common and this makes it easier for the disease to spread.
The human factors
Exposure of bare skin on a nightly basis, from dusk until dawn results in the spread of the disease.
The human factors
People living in overcrowded conditions provide an easier target for the mosquitoes.
The environmental factors
These are factors created by the background environment.
The environmental factors
Hot wet climates such as those experienced in the tropical rainforests or monsoon areas of the world.
The environmental factors
Regularly flooded areas with poor drainage which have standing water for long periods.
The environmental factors
Areas of shade in which the female mosquito can digest human blood.
MALARIAA disease of the developing world
Describe, describe and evaluate, describe, and explain, assess the effectiveness of measures/strategies/methods used to control/combat the spread of the disease.
MALARIA Control methods and their effectiveness
MALARIA Control methods and their effectiveness
Attempts to eradicate the mosquitoes:
MALARIAAttempts to eradicate the mosquitoes:
Insecticides(all oil-based) – eg DDT – however this was deemed environmentally harmful – impacts on the food chain. In addition the mosquitoes build up a resistance to chemical insecticides. Malathion was popular – now banned by EU.
MALARIAAttempts to eradicate the mosquitoes:
However countries which haven’t used DDT for decades (South Africa, Ethiopia, Mozambique, and Zambia) are now using it again for indoor spraying at lower concentrations.
MALARIAAttempts to eradicate the mosquitoes:
It is proving effective, as the mosquitoes seem to have lost their tolerance for it. Its environmental effects should be reduced as this is not the blanket spraying of the past.
MALARIAAttempts to eradicate the mosquitoes:
Mustard seeds – become wet and sticky and drag mosquito larvae under the water – this drowns them.
MALARIAAttempts to eradicate the mosquitoes:
Vegetable oil sprayed on the surface of standing water suffocates the mosquito larvae.
Only a thin film required, but environmental side effects to consider.
MALARIAAttempts to eradicate the mosquitoes:
Egg-white sprayed on water – suffocates larvae by clogging up their breathing tubes. Perhaps impractical and wasteful of food.
MALARIAAttempts to eradicate the mosquitoes:
Bti bacteria grown in coconuts. Fermented coconuts are, after a few days, broken open and thrown into mosquito infected ponds. The larvae eat the bacteria and have their stomach lining destroyed!!
MALARIAAttempts to eradicate the mosquitoes:
Cheap, environmentally friendly and 2/3 coconuts will control a typical pond for up to 45 days. However, wastes potential food.
MALARIAAttempts to eradicate the mosquitoes:
Larvae eating fish – effective (provided they aren’t eaten before the end of the malaria season) and a useful additional source of protein.
MALARIAAttempts to eradicate the mosquitoes:
Drainage of swamps and standing water – requires much effort – not always practicable in the tropics with constantly high rainfall.
MALARIAAttempts to eradicate the mosquitoes:
Planting eucalyptus trees that soak up excess moisture. However they are non native trees and often struggle to adapt to the conditions. They are also cut down for fuel use.
MALARIAA disease of the developing world
Treating those suffering from malaria:
MALARIATreating those suffering from malaria:
Drugs
Chloroquine – easy to use/cheap but mosquitoes have developed resistance to it
MALARIA
Treating those suffering from malaria: Drugs
Larium – powerful, greater protection – but can have harmful side-effects
MALARIA
Treating those suffering from malaria: Drugs
Malarone – fairly new drug – said to be 98% effective – few side effects
MALARIATreating those suffering from malaria:
Artemisinin – from the Artemisia plant - is showing real promise, but fears of resistance build-up mean it should only be used in combination treatments to maintain effectiveness.
MALARIATreating those suffering from malaria:
Vaccines – none yet available. Several have looked promising and led to field trials eg. in the Gambia, but have not prevented malaria infections.
MALARIAPrevention of infection:
Education programmes in the use of insect repellents eg Autan, DEET. Often unable to afford them(DEET has toxicity allegations)
Covering the skin when the mosquitoes are most active.
MALARIAPrevention of infection:
MALARIAPrevention of infection:
Mesh coverings over windows/door openings to keep mosquitoes out, often not practical.
MALARIAPrevention of infection:
Sleep under a treated mosquito net. Frequently unaffordable, even charities like Merlin can’t give them away.
MALARIAPrevention of infection:
The WHO ‘Roll back malaria’ campaign, and the Bill and Melinda Gates Foundation ($50M donated to fighting malaria so far) hope to make bed nets widely available by 2015.
MALARIAPrevention of infection:
Sumitomo of Japan, and US oil company Exxon have combined to produce insecticides and resins at cost, which enable the cheap production of mosquito nets which last more than 5 years.
MALARIAA disease of the developing world
How would eradication or control of the disease benefit developing countries?
MALARIAHow would eradication or control of the disease benefit
developing countries?
Saving money on health care, medicine, doctors, drugs etc.
MALARIAHow would eradication or control of the disease benefit
developing countries?
Reduction in the national debt, allowing money to be spent internally on health, education, housing etc.
MALARIAHow would eradication or control of the disease benefit
developing countries?
Healthier workforce, increasing productivity, escape from subsistence farming.
MALARIAHow would eradication or control of the disease benefit
developing countries?
Longer life expectancy, decreased infant mortality rate, and therefore decreased birth rates.
MALARIAHow would eradication or control of the disease benefit
developing countries?
A reduction in rural to urban migration as effective treatment given to country dwellers, thereby reducing pressure on cities.
MALARIA How would eradication or control of the disease benefit
developing countries?
More tourists may be attracted if there was less risk of contracting malaria – more job opportunities, foreign currency earnings, increased prosperity.
Music
Fila Brazillia
The bugs will bite
Album - A Touch Of ClothFour Tet
No more mosquitoes
Album - PauseRob Dougan
Nothing at all
Album Furious Angels
Pictures provided by the 2010-2011 Geography Higher class Portree High School
Updates on the fight against Malaria
The WHO reported recently that it expects Artemisinin to have become almost ineffective in the next 4 to 5 years, owing to resistance becoming widespread in the Plasmodium parasite.
The latest scientific development is WMD (weapon of mosquito destruction) which is in the lab development stage (sponsored by the Gates Foundation).
This involves equipment which detects the wing beat of female mosquitoes and zaps them with a laser. This makes them less likely to bite, and therefore to breed.