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    does anybody know anything about DDT and malaria? im doing a piece of work and need some opinions! this isnt a im too lazy to do my homework thread cos i have been working on it for just over 2 days i just wanted some friendly opinions on the uses of DDT and what you think would be appropriate short term and long term policies for dealing with malaria throughout the world????

    any help would be much appreciated!

    ruthie!
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    (Original post by ruthie)
    does anybody know anything about DDT and malaria? im doing a piece of work and need some opinions! this isnt a im too lazy to do my homework thread cos i have been working on it for just over 2 days i just wanted some friendly opinions on the uses of DDT and what you think would be appropriate short term and long term policies for dealing with malaria throughout the world????

    any help would be much appreciated!

    ruthie!
    The use of DDT to fight malaria has been more than unsuccessful. In the 60s, the early time of development work, there were serious trys to extinguish the Anopheles mosquito, but looking at Africa (as one example) it is completely clear that this could never work: they sprayed houses and villages, but in a rural area??? These little beasts sit everywhere in the bushed, they just came back and are now resistant. Applause!
    Currently, there is no method to prevent malaria. There are only prevention pills that prevent you from dying and lessen the syndroms and there are diferent treatments, chinin (already some resistance though) etc.
    Long term policies? The only way to prevent malaria is to cut all the bushes in a certain area around houses, but that isn´t very practicable. I think the best policy would be to give the people free access to the cheap drugs to prevent the horrible death rates. In fact, most people in Africa cannot afford a pack of Fanzida or similar pills, even though they costs less than a Euro.
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    thanks very much!!! that was a huge help! very grateful! ive written almost 3 pages and still havent a clue what im talking about
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    (Original post by ruthie)
    thanks very much!!! that was a huge help! very grateful! ive written almost 3 pages and still havent a clue what im talking about
    I did an essay on malaria for last term, its got some bits about DDT in it, if its helpful i can send you the relavent bits?
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    (Original post by Chicken)
    I did an essay on malaria for last term, its got some bits about DDT in it, if its helpful i can send you the relavent bits?
    any help would be fantastic! not that it will be marked,my teacher doesnt know what marking is grrr. I think im doing it for my own peace of mind!
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    (Original post by ruthie)
    any help would be fantastic! not that it will be marked,my teacher doesnt know what marking is grrr. I think im doing it for my own peace of mind!
    I've actually just found my essay, and it hasn't got about DDT in it at all, but i've written about all the drugs used in recent times to treat malaria if thats helpful?
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    (Original post by Chicken)
    I've actually just found my essay, and it hasn't got about DDT in it at all, but i've written about all the drugs used in recent times to treat malaria if thats helpful?
    oh ok dont worry, i think i have those, its more the DDT as its a chemistry thing! but thanks anyway and thanks for looking for it!
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    (Original post by ruthie)
    oh ok dont worry, i think i have those, its more the DDT as its a chemistry thing! but thanks anyway and thanks for looking for it!
    Sorry! My memory doesn't go back to November (thats when I wrote it!), we had a whole lecture as part of a course of chemistry-relavent lectures, and my coursework at the end was an essay on a subject on the lecture that interested me most. I think its quite an interesting subject.
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    (Original post by ruthie)
    does anybody know anything about DDT and malaria? im doing a piece of work and need some opinions! this isnt a im too lazy to do my homework thread cos i have been working on it for just over 2 days i just wanted some friendly opinions on the uses of DDT and what you think would be appropriate short term and long term policies for dealing with malaria throughout the world????

    any help would be much appreciated!

    ruthie!
    just state the obvious approaches to reducing the mosquito population (as it the vector for the malaria/plasmodium protozoan), such as spraying oil on the surface of stagnant ponds (as mosquito eggs are laid here). as it occurs mainly in marshy areas, reducing the amount of wetlands may also help. you can always mention natural resistance, as exhibited by people with heterzygous alleles for sickle celled anaemia in africa.
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    I had a lecture on this 2 weeks ago.

    Basically, at the moment the vector control measures are as follows

    Chemical control agaist immature stages

    - polystyrene balls in pit latrines - stops insects getting to surface to lay eggs

    - larvicides in water containers

    - Insect Growth Regulators (IGRs) - inhibit chitin formation, targets specific mosquitos and stops them being able to infect. high costs involved.

    Chemical control against adult vectors
    - Household spraying residual insecticides - kills endophillic, endophagic malaria vectors (mosquitos)

    - Mists, fogging etc outside, used against exophillic vectors. No residual effects though. Used to prevent epidemics

    - Protection (insecticide treated materials (ITMs), bednets (ITNs) to protect against anthropophagic vectors, clothing against daytime biters

    Biological control

    - larvicidal pathogens - i.e. eat the pathogen. inactive and environmentally safe, but expensive.

    - larvivorous fish

    - genetic control - e.g. release of sterile males

    - Cattle can also be treated with insecticide as a bait trap

    To control it you need to work bottom up. There's no use putting into place measures from the top i.e. goverment, if the people at the bottom of the chain are unable to participate, i.e. immunise themselves or whatever. The best method is to educate the people about how to stop the spread of the vector, i.e. put polystyrene balls in pit latrines, insecticide, mosquito nets etc, and just generally stop the biting rate of the mosquitos. there's big complicated formulas to work that out but i won't go into that. people are encouraged to spray their household with insecticides, although this is costly. bed nets are encouraged, and ITNs as a human bait trap (mosquito lands on net and promptly dies). if the whole village uses the nets, then the amount of mosquitos around will gradually decrease. the more households protected, the less vectors around, the less spread of the disease.

    Eradication of malaria hasn't happened for a variety of reasons, including vectors becomining resistant to the use of insecticides, and the reproductive capacity of the vectors, only takes 7-12 days to complete the life cycle. human reasons inculde the rapid urban growth, low political priority and industrialisation of disposible packaging. Inadequate piped water and storage of water in cisterns also contributed.

    Malaria is eradicated in portugal today, after laws were brought in requiring the regular drainage of rice fields, to stop build up of stagnant water, which is a breeding ground for the vectors. Paddy drainage every 17 days (because egg to adult vector takes 18 days) reduced larvae population by 80% in 4 years.
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    just read the messages posted while i was typing that and it's more aimed towards biology than chemistry, so maybe not what you're looking for.
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    (Original post by picju96)
    I had a lecture on this 2 weeks ago.

    Basically, at the moment the vector control measures are as follows

    Chemical control agaist immature stages

    - polystyrene balls in pit latrines - stops insects getting to surface to lay eggs

    - larvicides in water containers

    - Insect Growth Regulators (IGRs) - inhibit chitin formation, targets specific mosquitos and stops them being able to infect. high costs involved.

    Chemical control against adult vectors
    - Household spraying residual insecticides - kills endophillic, endophagic malaria vectors (mosquitos)

    - Mists, fogging etc outside, used against exophillic vectors. No residual effects though. Used to prevent epidemics

    - Protection (insecticide treated materials (ITMs), bednets (ITNs) to protect against anthropophagic vectors, clothing against daytime biters

    Biological control

    - larvicidal pathogens - i.e. eat the pathogen. inactive and environmentally safe, but expensive.

    - larvivorous fish

    - genetic control - e.g. release of sterile males

    - Cattle can also be treated with insecticide as a bait trap

    To control it you need to work bottom up. There's no use putting into place measures from the top i.e. goverment, if the people at the bottom of the chain are unable to participate, i.e. immunise themselves or whatever. The best method is to educate the people about how to stop the spread of the vector, i.e. put polystyrene balls in pit latrines, insecticide, mosquito nets etc, and just generally stop the biting rate of the mosquitos. there's big complicated formulas to work that out but i won't go into that. people are encouraged to spray their household with insecticides, although this is costly. bed nets are encouraged, and ITNs as a human bait trap (mosquito lands on net and promptly dies). if the whole village uses the nets, then the amount of mosquitos around will gradually decrease. the more households protected, the less vectors around, the less spread of the disease.

    Eradication of malaria hasn't happened for a variety of reasons, including vectors becomining resistant to the use of insecticides, and the reproductive capacity of the vectors, only takes 7-12 days to complete the life cycle. human reasons inculde the rapid urban growth, low political priority and industrialisation of disposible packaging. Inadequate piped water and storage of water in cisterns also contributed.

    Malaria is eradicated in portugal today, after laws were brought in requiring the regular drainage of rice fields, to stop build up of stagnant water, which is a breeding ground for the vectors. Paddy drainage every 17 days (because egg to adult vector takes 18 days) reduced larvae population by 80% in 4 years.
    Hmmmm... I fully believe this is the recent state of science but are these ideas practical for the malaria areas (Africa, south america, asia)? I doubt it a bit!
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    Bottom up measures like I mentioned the ITN's are currently being used in places like that. In Vietnam/China 2.5 million households are currently protected. They are being used in Singapore against Aedes aegypti very sucessfuly, and have been for 20 years. They have introduced penalties for anyone found to be 'breeding mosquitos' that are very effective. Community preparing of INTs are found everywhere, because it is so cheap to do, and effective. I have a picture in my lecture notes of african women soaking their sheets in a big tin bath. When malaria exploded in India in the early 1990s, measures were introduced like roof water storage tanks fitted with screens, and slow release organophosphates larvicides (e.g. Temphos) which are cheap and easy to come by, and effective too. Cows are kept by people in places like africa and sprayed with insecticides to act as bait for the mosquitos. this is very effective especially against An. stephensi, where there was an immediate elimination of ectoparasites, and an inproved milk yield too. In El Salvador, the genetically modified sterile males were introduced, which greatly reduced the biting rate.

    Drugs are only used for travellers, I'm on them at the moment because I went to India last week. people living in the malarious area have a certain amount of resistance anyway.
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    (Original post by ruthie)
    thanks very much!!! that was a huge help! very grateful! ive written almost 3 pages and still havent a clue what im talking about
    The DDT programme was working very well, and some areas are still free because of it (of course it had huggggggge environmental consequences, and mosquitoes became resistant) but DDT did do a good job against yellow fever and dengue fever in S. America, so swings and roundabouts really.

    The main problem in Africa was that the DDT reduced population numbers and as a result fewer people were exposed to malaria. When the programme was stopped, the mosquitoes returned, and so did the malaria. AS a consequence of lack of exposure, huge tracts of the population were suceptible, and so the malaria spread like crazy and killed many (hence the big disaster of the whole ddt programme).
    Nowadays there are many programmes to try to control malaria. It's difficult to stop mosquitoes in Africa especially in the rainy season, because larvae quickly mature in random puddles. The main method of control is the mosquito nets. A simple device but yet quite effective, especially when treated with an insecticide. DEET is also often applied. This is a repellent which works by masking some of the bodily odours which attract the mosquitoes to us (lactic Acid in your sweat actually).
    In china they have a brilliant system with paddy fields which normally would allow for lots of mosquito larva to grow (because they are flooded fields) instead they put fish in the water which eat all the larvae. So mosquito numbers are reduced, and theres a source of protein for the farmers.
    Remember that 90% of the mortality in sub-sahara area is due to malaria - mainly the Plasmodium Falciparum species .
    Any help needed, just ask and I'll go into detail. (it'll be good revision for my parasitology exams)
    J
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    (Original post by picju96)
    I had a lecture on this 2 weeks ago.

    Basically, at the moment the vector control measures are as follows

    Chemical control agaist immature stages

    - polystyrene balls in pit latrines - stops insects getting to surface to lay eggs

    - larvicides in water containers

    - Insect Growth Regulators (IGRs) - inhibit chitin formation, targets specific mosquitos and stops them being able to infect. high costs involved.

    Chemical control against adult vectors
    - Household spraying residual insecticides - kills endophillic, endophagic malaria vectors (mosquitos)

    - Mists, fogging etc outside, used against exophillic vectors. No residual effects though. Used to prevent epidemics

    - Protection (insecticide treated materials (ITMs), bednets (ITNs) to protect against anthropophagic vectors, clothing against daytime biters

    Biological control

    - larvicidal pathogens - i.e. eat the pathogen. inactive and environmentally safe, but expensive.

    - larvivorous fish

    - genetic control - e.g. release of sterile males

    - Cattle can also be treated with insecticide as a bait trap

    To control it you need to work bottom up. There's no use putting into place measures from the top i.e. goverment, if the people at the bottom of the chain are unable to participate, i.e. immunise themselves or whatever. The best method is to educate the people about how to stop the spread of the vector, i.e. put polystyrene balls in pit latrines, insecticide, mosquito nets etc, and just generally stop the biting rate of the mosquitos. there's big complicated formulas to work that out but i won't go into that. people are encouraged to spray their household with insecticides, although this is costly. bed nets are encouraged, and ITNs as a human bait trap (mosquito lands on net and promptly dies). if the whole village uses the nets, then the amount of mosquitos around will gradually decrease. the more households protected, the less vectors around, the less spread of the disease.

    Eradication of malaria hasn't happened for a variety of reasons, including vectors becomining resistant to the use of insecticides, and the reproductive capacity of the vectors, only takes 7-12 days to complete the life cycle. human reasons inculde the rapid urban growth, low political priority and industrialisation of disposible packaging. Inadequate piped water and storage of water in cisterns also contributed.

    Malaria is eradicated in portugal today, after laws were brought in requiring the regular drainage of rice fields, to stop build up of stagnant water, which is a breeding ground for the vectors. Paddy drainage every 17 days (because egg to adult vector takes 18 days) reduced larvae population by 80% in 4 years.
    Just read this. It's really quite excellent. I think i'm going to print this out for quick revision notes lol
    J
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    (Original post by foolfarian)
    The DDT programme was working very well, and some areas are still free because of it (of course it had huggggggge environmental consequences, and mosquitoes became resistant) but DDT did do a good job against yellow fever and dengue fever in S. America, so swings and roundabouts really.

    The main problem in Africa was that the DDT reduced population numbers and as a result fewer people were exposed to malaria. When the programme was stopped, the mosquitoes returned, and so did the malaria. AS a consequence of lack of exposure, huge tracts of the population were suceptible, and so the malaria spread like crazy and killed many (hence the big disaster of the whole ddt programme).
    Nowadays there are many programmes to try to control malaria. It's difficult to stop mosquitoes in Africa especially in the rainy season, because larvae quickly mature in random puddles. The main method of control is the mosquito nets. A simple device but yet quite effective, especially when treated with an insecticide. DEET is also often applied. This is a repellent which works by masking some of the bodily odours which attract the mosquitoes to us (lactic Acid in your sweat actually).
    In china they have a brilliant system with paddy fields which normally would allow for lots of mosquito larva to grow (because they are flooded fields) instead they put fish in the water which eat all the larvae. So mosquito numbers are reduced, and theres a source of protein for the farmers.
    Remember that 90% of the mortality in sub-sahara area is due to malaria - mainly the Plasmodium Falciparum species .
    Any help needed, just ask and I'll go into detail. (it'll be good revision for my parasitology exams)
    J
    Yeah, I believe you every word. But the original question was the long term solution.
    Malaria has always killed many in Africa, just because they get it several times in their lives and old people just die of it one day (or, tragically, kids). Especially in combination with malnutrition the fever kills one in two days sometimes. But the 90% stats is not correct, it is ratehr due to the fact that the diagnosis in African hospitals often works randomly: they diagnose what they can... I have seen it! People go to the hospital with some sickness. The doctor takes their blood, looks through the microscope, sees some strangely shaped things, says Malaria! The guy dies of whatever and the death certificate says Malaria.
    Sometimes these effects are even desirable for people. In South Africa a strangely high number of patients dies of pneumonia. But actually they die of AIDS and the family doesn´t want to admit it for social reasons.

    Back to Malaria, I think the only way would be the mosquito nets, but of course people don´t have money for that. ANd if you work in the bush you need full body clothing or you get bitten twenty times per minute. But in many regions people don´t even really wear clothes! Besides the fact that many people don´t believe Malaria is transfered by mosquitos.
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    (Original post by foolfarian)
    Just read this. It's really quite excellent. I think i'm going to print this out for quick revision notes lol
    J
    Thank you! It was helpful typing it out for my revision too, to see actually how much I knew!
 
 
 
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