African Letter on World Malaria
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25 th April 2011 To: African Ministers of Health Dear Hon. Ministers, We the undersigned public health and environmental NGOs from Africa and elsewhere share a deep concern about the catastrophic public health tragedy that malaria represents for Africa and other regions. On the occasion of World Malaria Day on April 25, we urge you to conduct the fight against malaria using the most effective, least toxic, sustainable malaria control approaches. We urge you not to allow a handful of people with ulterior motives to derail this movement with false arguments manufactured to rehabilitate ineffective interventions which are harmful to human health — such as widespread spraying of the insecticide DDT i inside homes. Our groups fully support the approach to DDT outlined in the Stockholm Convention, which allows use only for malaria vector control in accordance with WHO guidelines, in countries where no locally safe, effective and affordable alternatives are currently available. The Convention emphasizes attention to alternatives that will allow for ultimate elimination of DDT. Through a process initiated by the Stockholm Convention- called the Global Alliance for Alternatives to DDT — the global community is moving towards finding safe effective ways to control malaria and phase out this dangerous toxic chemical. We urge you to support this process. Over the past few years there has been an increase in misinformed calls for using toxic- and ultimately ineffective strategies for malaria control such as Indoor Residual Spraying with the insecticide DDT. A barrage of misinformation and falsehoods is being spread by a few advocates of DDT, whose concern for malaria control is questionable and their larger goal seems to be to undermine the global processes moving towards finding alternatives to this toxic insecticide. Leading malaria experts Dr Charles Mbogo from Kenya Medical Research Institute and Dr Hans Herren, former Director General of the International Center for Insect Physiology and Ecology in Kenya have said about these pro-DDT advocates that “Their habit of reducing the complex issue of malaria control to a single, dichotomous choice between DDT and malaria is a dangerous oversimplification and a distraction from the critical dialogue on how to effectively combat malaria around the world —particularly in African communities.” ii A few of the key myths that these proponents of DDT spread are: Myth: Western countries, like the United States of America, controlled malaria largely by using DDT Fact: While DDT spraying was a tool used by the United States’ National Malaria Eradication Program iii , it didn't commence until half way through 1947, by which time, non- DDT malaria control had already caused malaria morbidity and mortality to plummet and the area of endemic malaria to shrink to fraction of the size it had once been. Other means of malaria control — such as improved sanitation, environmental management, access to health care, and generally rising standards of living which brought things like screened windows to rural areas in southern United States where malaria was prevalent- had already done most of the work by the time DDT became available. U.S. government scientists stated they "kicked a dying dog" when they used DDT for malaria control, as a majority of the disease control had already occurred by the time DDT appeared on the scene. Elsewhere, the advent of DDT initially scored victory after victory in the fight against malaria — nearly eliminating the deadly disease in many areas. But these wins were mostly short- lived, as mosquitoes rapidly developed resistance to the chemical. Today, its effectiveness is a fraction of what it once was; meanwhile an arsenal of better and safer anti-malaria 1 interventions has been developed, including effective chemical-free strategies. So while experts agree that DDT can still occasionally play a role in a multi-pronged approach to malaria control, it’s usefulness is limited. Myth: DDT is the most effective tool in the fight against malaria Fact: While the World Health Organization’s initial efforts to eradicate malaria worldwide with a massive DDT spray program in the 1950s and 60s helped to control malaria in many places, it was unable to wipe out malaria. Resistance to DDT among malaria-carrying mosquitoes was one of the many reasons for the failure of WHO’s malaria eradication effort from that era. Resistance to DDT in mosquitoes was identified in Africa as early as 1955, and by 1972 nineteen species of mosquito worldwide were resistant to DDT. Latest data from the African Network on Vector Resistance to Insecticides shows very high rates of resistance throughout Africa — especially in Western and Eastern Africa. High rates of resistance to DDT in mosquitoes — some reportedly as high as 90% in test cases — has been reported from India recently iv . Even in today’s spraying conditions, often DDT intended for public health use is diverted to illegal agricultural use, hastening the development of resistant mosquito populations. Such illegal agricultural use of DDT has economic consequences — limiting agricultural exports to foreign markets. New research shows that in some circumstances spraying DDT is not only ineffective, but it may actually increase malaria transmission. It has to do with repellency and community-level effects of insecticides. Studies have shown that some mosquitoes that are resistant to DDT's toxic effects are still repelled by it. The problem is that this repellency means that it is more likely that mosquito will bite a neighbor instead of residents of a house sprayed with DDT, and this also decreases the chances that the mosquito will pick up a lethal dose of insecticide from walls or treated bed nets in the house which has DDT sprayed. This "behavioral avoidance" of DDT has been cited as one of the reasons for the declining effectiveness of African anti-malaria campaigns based on DDT. With treated bednets only, the people who have them are protected, but the people who don't have them are also protected — albeit to lesser extent — because in addition to providing a physical barrier between people and mosquitoes, the nets also kill mosquitoes, meaning there are less of them to transmit the disease. Adding a repellent like DDT results that some of those mosquitoes that might have been killed are instead repelled, and end up biting someone else — the so called ‘deflected bite’. v Prevention is crucial to malaria control, and effective programs are in place in many countries that combine a range of preventive approaches, including treated bed nets, selective use of indoor residual spraying, fish predators of mosquito larvae, improved sanitation, water drainage, public education (improved health seeking behavior), and surveillance of cases in malarial areas. Community-based integrated vector management, rather than reliance on a single tool, has proven the key to successful programs. vi Malaria treatment is very crucial to its prevention. Recent introduction of ACTs (Artemisinin Combination Therapy) has proved very effective in eliminating the parasite from the human host, thereby rendering mosquito bites malaria parasite free. ⇒ Vietnam reduced malaria deaths by 97% and malaria cases by 59% when it switched in 1991 from trying to eradicate malaria using DDT to a DDT-free malaria control program involving early diagnosis, distribution of drugs and mosquito nets along with widespread health education organized with village leaders. ⇒ A program in central Kenya is focusing on reducing malaria by working with the community to improve water management, sanitation, cleaning up of cities, using biological controls, and distributing mosquito nets in affected areas. ⇒ Mexico shifted away from DDT use with an integrated approach that combined early detection of malaria cases and prompt medical treatment, community participation in 2 notification of malaria cases, cleaning of sites where mosquitoes breed, and low-volume chemical control with pyrethroid and other less toxic pesticides as part of a resistance management strategy. Better distribution of malaria control drugs and community wide regimes of these drugs — both prophylactic and curative — played a crucial role in the success in Mexico and other areas where malaria incidents dropped and have remained under control. Myth: DDT is harmless to human health Fact: A growing body of scientific literature has documented the risk of long-term human health impacts associated with DDT exposure. Increased reliance on DDT for malaria control puts African children at risk of significant neurodevelopmental delays, and families at risk of higher miscarriage rates, poor sperm quality and other fertility problems. Unfortunately, this evidence has been disregarded by public health officials in some malarial areas. In a 2011 paper South African expert Henk Bouwman has cautioned that “an unqualified statement that DDT as used in IRS is safe is untenable.” He concluded that this “ignores the cumulative indications of many studies.” vii In its latest 2011 assessment of DDT, the World Health Organization states that inter alia “that there is an acute poisoning hazard for children with accidental ingestion of DDT,” and notes that while exposures to residents of DDT-treated homes generally “are below potential levels of concern for populations,” and that “in some areas, the exposures in treated residences have been higher than potential levels of concern. ... Of particular concern would be women of childbearing age who live in DDT