DDT for Malaria Control - A Flash Presentation
Public Health Insecticides
Insecticides are a vital component in controlling vector-borne diseases such as malaria. Currently, there is only one vector-borne disease for which there is an effective vaccine - yellow fever. Even with the existence of a yellow fever vaccine, insufficient vaccination rates lead to serious outbreaks every year; which serves as a constant reminder of the need for effective, comprehensive vector control with safe, reliable insecticides.
AFM was founded during the fight to save DDT for malaria control, and has continued to advocate for the sound, judicious use of insecticides in disease control for almost a decade. AFM's most recent contributions include: the April 2010 launch of the book The Excellent Powder: DDT's Political and Scientific History
by Prof. Donald Roberts and Richard Tren, with Roger Bate and Jennifer Zambone. The book attempts to set the record straight on DDT, debunking the myths that led to its decline in use in malaria control in many countries, and the subsequent impact on malaria eradication efforts. As Marjorie Hecht writes in her review of the book
, "this political and scientific history of DDT should be required reading in environmental science courses..." An excerpt of the book can be found here
In June 2010, AFM co-hosted a briefing on Capitol Hill
in conjunction with the Congressional Malaria Caucus, aiming to increase understanding about integrated vector control and the crucial role of public health insecticides in malaria prevention programs.
AFM also advocates for more investment, both public and private, in the search for new, effective and safe insecticides.
Just as pathogens develop resistance to medicines, mosquitoes and other insects develop resistance to insecticides. AFM believes that the solution to insecticide resistance is not, as some would argue, to limit and reduce the use of insecticides, but rather to find ways to manage resistance and most importantly, to find new chemicals. It is also important to recognize that different chemicals act in different ways. Toxicity is not the only mode of action that is important for malaria control - spatial repellency and contact irritancy also play very important roles - described by John Grieco et al
as well as in numerous other reports and in the scientific literature.
AFM is frustrated with the lack of leadership and vision for the development of new insecticides. The Bill and Melinda Gates Foundation's investment in the Innovative Vector Control Consortium
is extremely valuable; however, AFM believes much more can and should be done by governments, UN agencies and the private sector to bring new products to market. Yet in 1997, the World Health Assembly passed a resolution calling on nations to reduce their reliance on insecticides
. As AFM's report Bias and Neglect
explains, while various WHO and UN reports have acknowledged the growing problem of insecticide resistance, few propose solutions for the lack of profit incentive in investing in public health insecticides. Contrast this with the leadership, numerous partnerships, legislation, and creative solutions designed to address the limited profit incentive in malaria medicines and vaccines.
Legislation and onerous regulations also discourage investment in public health insecticides. The European Parliament recently approved new legislation that could effectively ban a number of chemicals used in popular pesticides for agriculture. While the legislation does not specifically target public health chemicals, almost all of the insecticides used to treat bednets and for IRS are derived from agricultural chemicals. The public health market makes up a small fraction of the total insecticides market. Therefore without an agricultural market, it would be financially unviable to produce chemicals purely for disease control.
Early drafts of the EU legislation would have introduced an unscientific and capricious set of rules governing the use of insecticides - this would have removed numerous products from the market that are currently used in malaria control and would have damaged critical investment in this area. In response to these poorly formulated and damaging draft regulations, AFM coordinated a letter of petition
to the EU signed by over 160 senior scientists. AFM also reached out to European Members of Parliament and the EU Commission. Advocacy against the regulations by farming groups, industry and the public health community helped to strip out much of the potentially harmful and unscientific language in the legislation. Some products could still be banned, even without sound scientific evidence, and overall the legislation still creates uncertainty; but it is likely to be less damaging than early drafts.
AFM believes that the abandonment of early drafts of the legislation by European Parliamentarians demonstrates the importance of advocacy in favor of good science and common sense. Much more can and must be done to reverse the many years of harm that has been caused by an anti-insecticides agenda that has sought to limit the use of these products to save lives from preventable diseases.
In opposition to those who seek to use insecticides in disease control are some environmentalist groups that actively campaign against the use of public health insecticides. They propose the use of larvivorous fish and environmental management, amongst other measures, as alternatives to insecticide use. The reality however is that on the whole these alternatives are not scientifically proven solutions and would be applicable only in very limited situations. The most disturbing feature of the environmentalist campaign is that they tend to focus solely on the risks of using insecticides and not on the risks posed by the diseases themselves. Given the immediate and very deadly risks posed by mosquitoes, AFM contends that any potential risks from insecticides are far lower, particularly when used judiciously and according to WHO guidelines.
Along with environmentalist antagonism, public health insecticides, particularly DDT, face increasing opposition over concerns for human safety. These concerns are unfounded - to date, no properly replicated and confirmed studies have been able to show that environmental exposure to DDT has a detrimental effect on human health. AFM recently responded (here
) to various studies claiming that DDT is a cause of harm to human health. One recent study, which has been the subject of controversial media coverage, claims that DDT sprayed indoors to control malaria increases the probability that a boy will be born with a urogenital birth defect. AFM responded to this study
, pointing out the inconsistencies of data, problems of interpretation, and other shortcomings. The study does not provide evidence of a cause-and-effect relationship, nor does it establish convincing arguments of harm caused by DDT that would outweigh the enormous health benefits it provides. AFM believes it is not the careful and judicious use of insecticides, but rather studies like these that pose great risks to the health and welfare of people in malarious areas. These studies undermine the use of what remains one of the safest and most effective methods of malaria prevention.
AFM is calling on WHO, donor agencies, and other stakeholders to:
1) Dramatically increase funding into the search for insecticides specifically designed for disease vector control;
2) Undertake a regulatory impact assessment to establish the additional and unintended costs of new anti-insecticide regulations, with emphasis on how new regulations impede development of new public health insecticides;
3) Address and reform the regulatory and in-country registration procedures that discourage investment in public health insecticides;
4) Consider legislation to create incentives for the development of insecticides for public health;
5) Invalidate the World Health Assembly resolution 50.13, which calls on countries to reduce reliance on the use of insecticides for disease control. Pass a new resolution establishing the importance of insecticides in disease control and calling for new public and private investment in public health insecticides;
6) Invest in training and employing scientists, entomologists, and public health professionals skilled in vector control in countries endemic for vector-borne diseases, particularly malaria and dengue;
7) Recognize that public health insecticides have modes of action other than toxicity and that these play a vital role in disease control; and
8) Support advocacy efforts to communicate and explain the urgent need for new public health insecticides, reduce the barriers to their deployment, and better represent the voices of people at risk from vector-borne diseases.
AFM also invites you
to get involved in the fight to save lives from preventable diseases such as malaria. Advocacy and leadership for new public health insecticides is absent and desperately needed. You can help to fill this void by donating to our work
, distributing our material, speaking to your Congressman or Member of Parliament, or by simply challenging those who seek to limit the use of live-saving insecticides.