- Email: [email protected]
DDT: a polluted debate in malaria control
Comment
There were no data to confirm or explain a causal link between the treatment and the outcomes. The response of acetylcholinesterase and neuromuscular function were not measured, nor was the effect of treatment on the pesticide concentration. Crucially, the specific pesticide ingested was not even confirmed. There were also aspects of the trial design that might have inadvertently led to bias.6 For example, the trial was underpowered, there was no blinding, there was a small fixed-block size that could have undermined allocation concealment,7 and there was no reproducible algorithm for atropine dosing or pralidoxime cessation. These problems might relate to the limited support for clinical research in Asia, especially for independent clinical investigators outside the few centres of excellence. Most future studies on pesticide poisoning will be in such settings in developing countries.8 Some thought should be given as to how best to support more activity, because there is no coordinated international effort to address this problem at the moment, although there are lots of people, organisations, and governments who might be regarded as stakeholders. In a unique procedure supported by The Lancet, the reporting of this study was assisted by two reviewers, who reviewed most of the original data to assist the preparation of a revised manuscript, one of whom travelled on site to discuss critical issues with the authors. How much better would it have been to have this kind of advice before the trial starts? Pralidoxime is expensive, and high doses might be unaffordable in many places. An affordable pralidoxime preparation should be part of a public-health response to the considerable problem of pesticide poisoning in developing countries.8,9 We believe the drug will save lives,
particularly in places where high-tech equipment is not available and many die simply because a respirator cannot be provided for every patient who needs one.10,11 However, this public-health problem would also be helped by better research support for investigators such as Pawar and colleagues, who should be highly commended for their endeavours. *Peter Eyer, Nicholas Buckley Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Munich D-80336, Germany (PE); South Asian Clinical Toxicology Research Collaboration, Sri Lanka (PE, NB); and Clinical Pharmacology and Toxicology, Canberra Hospital, Canberra, ACT, Australia (NB) [email protected] We declare that we have no conflict of interest. 1
2 3 4
5
6
7 8 9 10
11
Pawar KS, Bhoite RB, Pillay CP, Chavan SC, Malshikare DS, Garad SG. Continuous pralidoxime infusion versus repeated bolus injection to treat organophosphorus pesticide poisoning: a randomised controlled trial. Lancet 2006; 368: 2136–41. Eyer P. The role of oximes in the management of organophosphorus pesticide poisoning. Toxicol Rev 2003; 22: 165–90. Johnson MK, Jacobsen D, Meredith TJ, et al. Evaluation of antidotes for poisoning by organophosphorus pesticides. Emerg Med 2000; 12: 22–37. Eddleston M, Eyer P, Worek F, et al. Differences between organophosphorus insecticides in human self-poisoning: a prospective cohort study. Lancet 2005; 366: 1452–59. European Association of Poisons Centres and Clinical Toxicologists/American Academy of Clinical Toxicology. Position paper: ipecac syrup. J Toxicol Clin Toxicol 2004; 42: 133–43. Schulz KF, Chalmers I, Hayes RJ, Altman DG. Empirical evidence of bias: dimensions of methodological quality associated with estimates of treatment effects in controlled trials. JAMA 1995; 273: 408–12. Schulz KF, Grimes DA. Generation of allocation sequences in randomised trials: chance, not choice. Lancet 2002; 359: 515–19. Buckley NA, Roberts D, Eddleston M. Overcoming apathy in research on organophosphate poisoning. BMJ 2004; 329: 1231–33. Eddleston M. Patterns and problems of deliberate self-poisoning in the developing world. QJM 2000; 93: 715–31. Shivakumar S, Raghavan K, Ishaq RM, Geetha S. Organophosphorus poisoning: a study on the effectiveness of therapy with oximes. J Assoc Phys India 2006; 54: 250–51. Eddleston M, Mohamed F, Davies JO, et al. Respiratory failure in acute organophosphorus pesticide self-poisoning. QJM 2006; 99: 513–22.
DDT: a polluted debate in malaria control A recent press statement from WHO about dichlorodiphenyltrichloroethane (DDT) and indoor residual spraying for malaria control1 caused a considerable stir, despite the fact that, in terms of policy, it merely re-iterated WHO’s endorsement of DDT as a useful insecticide for malaria control, albeit in a highly promotional way. In this recurring debate, arguments for and against DDT, as before, have been heated and mainly based on considerations far removed from the realities of malaria control. www.thelancet.com Vol 368 December 16, 2006
One group that criticised the WHO statement has inferred that my resignation from WHO’s Global Malaria Programme in September, 2006, was related to my opposition to its promotion of DDT.2 This assumption is erroneous. For many years, WHO’s malaria-control professionals have fought hard against pressure from various sides to ensure access in malaria-endemic countries to DDT.3 Hopefully, the statement now issued by the Global Malaria Programme1 will put an end to this debate, so that all countries that need DDT for malaria
Published Online December 7, 2006 DOI:10.1016/S01406736(06)69812-7
2111
Comment
Panos Pictures
The printed journal includes an image merely for illustration
control will have unfettered access to use it in accordance with WHO guidelines and with the Stockholm Convention on Persistent Organic Pollutants, if they are signatories to the latter. Meanwhile, remarks from the opposite camp have not lacked passion, conveying the impression that large-scale use of DDT for malaria control, so long held hostage to misguided concerns for the environment, will now save the lives of millions of people from malaria.4 This idea is not so simple. As pointed out in WHO’s new position statement, indoor residual spraying is an effective intervention, provided a programme infrastructure can be set up and maintained to include trained sprayers, supervisors, managers, stocks, equipment, and vehicles, that roads allow access to every village at the right time at least once a year, and that insecticides are not diverted to agriculture. The need to prevent diversion has been highlighted for DDT, but for malaria control it is equally important for other insecticides. Furthermore, especially in areas with intense and perennial transmission, it is essential to maintain the population’s long-term acceptance of spraying once or several times a year.5 In view of the difficulties encountered in maintaining indoor residual spraying, WHO has invested substantially in exploring other methods, especially insecticide-treated bednets. These nets have been effective in many rigorous trials,6 especially to reduce childhood mortality in Africa. Few trials have compared insecticide-treated nets and indoor residual spraying, but results so far suggest that the methods are more or less equal in efficacy.7 As pointed out by WHO,8 the two methods are similar 2112
in the way they work, although unlike indoor residual spraying, insecticide-treated nets can protect individual users or households. Few data exist for the use and cost-effectiveness of combining these two methods. In view of the substantial costs of prevention for the huge populations at risk, national programmes will generally need to choose one of these two methods for a specific geographical area. The choice of insecticide is secondary. Since only pyrethroids can be used for insecticide-treated nets, and pyrethroid resistance is emerging as a constraint on their effectiveness,9 the fact that four classes of insecticides can be used for indoor residual spraying should be one of the main reasons justifying renewed interest in this method. In the choice between indoor residual spraying and insecticide-treated nets, a WHO study group convened in 2004 noted that the decision should, in most cases, be based on operational factors.8 Because long-lasting insecticidal nets can be managed easily with minimum risk of diversion of insecticide, for most high-burden countries that have not developed an infrastructure for indoor residual spraying, the priority will be to ensure coverage of at-risk populations with such long-lasting nets. The renewed interest in indoor residual spraying could lead to interminable debates in countries about the pros and cons of DDT. Such discussions pit sectors against politicians when, in fact, a non-partisan commitment is needed desperately to protect individuals at risk of malaria with one of the two proven methods. Allan Schapira 1227 Genève-Acacias, Switzerland [email protected] I resigned my post as coordinator, vector control and prevention, of the Global Malaria Programme, WHO, on Sept 6, 2006, because of disagreements with the director of the programme about policy issues. 1
2
3 4
5
WHO. WHO gives indoor use of DDT a clean bill of health for controlling malaria. WHO promotes indoor residual spraying with insecticides as one of three main interventions to fight malaria. Sept 15, 2006: http://www.who. int/mediacentre/news/releases/2006/pr50/en/print.html (accessed Nov 15, 2006). Pesticide Action Network North America. Global coalition of health and toxic experts demand that WHO stop irresponsible promotion of DDT. Sept 26, 2006: http://www.panna.org/resources/newsroom/stopWhoProm otionDdt20060926.dv.html (accessed Nov 15, 2006). Schapira A. DDT still has a role in the fight against malaria. Nature 2004; 432: 439. Stossel J. Hooray for DDT’s life-saving come-back. Oct 4, 2006: http://www. townhall.com/columnists/JohnStossel/2006/10/04/hooray_for_ddts_lifesaving_comeback (accessed Nov 15, 2006). Global Malaria Programme. Indoor residual spraying: use of indoor residual spraying for scaling up global malaria control and elimination. 2006: http://malaria.who.int/docs/IRS-position.pdf (accessed Nov 9, 2006).
www.thelancet.com Vol 368 December 16, 2006
Comment
6 7
Lengeler C. Insecticide-treated bednets and curtains for preventing malaria. Cochrane Database Syst Rev 2004; 2: CD000363. Lengeler C, Sharp B. Indoor residual spraying and insecticide-treated nets. In: Murphy C, Ringheim K, Woldehanna S, Volmink J. eds. Reducing malaria’s burden: evidence of effectiveness for decision makers. Washington, DC: Global Health Council, 2003: 17–24.
8
9
Report of a WHO study group. Malaria vector control and personal protection. 2006: http://www.who.int/malaria/docs/WHO-TRS-936s.pdf (accessed Nov 9, 2006). Etang J, Chandre F, Guillet P, Manga L. Reduced bio-efficacy of permethrin EC impregnated bednets against an Anopheles gambiae strain with oxidasebased pyrethroid tolerance. Malar J 2004; 3: 46.
Art for women’s health The difference in the sexual and reproductive health status of women in developed and developing countries is vast. This disparity represents one of the starkest examples of social injustice of our time. About 530 000 pregnant women and 3 million newborn babies die every year because of complications related to pregnancy and childbirth. Almost all these deaths happen in developing countries.1 Similarly, sexually transmitted infections, reproductive-tract infections, cervical cancer induced by the human papillomavirus, and other gynaecological disorders disproportionately affect the most vulnerable and disenfranchised populations of women. Much could be done to rectify these situations if more people were informed about and mobilised to act towards the improvement of global sexual and reproductive health. Greater advocacy and support for sexual and reproductive health interventions—including information-based campaigns, for example—could lead to substantial changes in the dire conditions many women and their newborn babies currently endure. The intention of the Art for Health project is to contribute to these efforts in an innovative way. Specifically, the project uses contemporary art as a medium to increase people’s awareness of sexual and reproductive health issues around the world, particularly those that negatively affect the lives of women and their families. Participants at the XVIII World Congress of the International Federation of Gynecology and Obstetrics (FIGO)—in Kuala Lumpur, Malaysia, Nov 5–10, 2006— will be able to view the first set of contemporary artworks produced for the Art for Health project at WHO’s stand. The project is actively endorsed by the WHO Department of Reproductive Health and Research (RHR), which has commissioned 18 paintings and is sponsoring the first exhibition of a selection at the congress. The department is also using the artwork for promotional material and publications. The paintings that will be featured at the congress portray women from diverse ethnic and social backwww.thelancet.com Vol 368 December 16, 2006
grounds. Within the images are messages by the women themselves that call on the viewer to join them in a unified effort to better their lives and those of future generations. The statements incorporated into the two representative pieces accompanying this Comment are modifications of famous quotes of outspoken women2 and exemplify these interconnected themes of solidarity, agency, and collective action. “Same sky, same women”, for example, promotes awareness of an underlying tie connecting women around the world (figure 1). “I want to fight with dreams in my soul, with you” furthers this sentiment by asking viewers to engage in partnerships with women living in low-resource nations, partnerships that are characterised by mutual respect and geared
Published Online November 5, 2006 DOI:10.1016/S01406736(06)69642-6
Figure 1: Same sky, same women Elisabetta Farina, 2006, acrylic on canvas.
2113
There were no data to confirm or explain a causal link between the treatment and the outcomes. The response of acetylcholinesterase and neuromuscular function were not measured, nor was the effect of treatment on the pesticide concentration. Crucially, the specific pesticide ingested was not even confirmed. There were also aspects of the trial design that might have inadvertently led to bias.6 For example, the trial was underpowered, there was no blinding, there was a small fixed-block size that could have undermined allocation concealment,7 and there was no reproducible algorithm for atropine dosing or pralidoxime cessation. These problems might relate to the limited support for clinical research in Asia, especially for independent clinical investigators outside the few centres of excellence. Most future studies on pesticide poisoning will be in such settings in developing countries.8 Some thought should be given as to how best to support more activity, because there is no coordinated international effort to address this problem at the moment, although there are lots of people, organisations, and governments who might be regarded as stakeholders. In a unique procedure supported by The Lancet, the reporting of this study was assisted by two reviewers, who reviewed most of the original data to assist the preparation of a revised manuscript, one of whom travelled on site to discuss critical issues with the authors. How much better would it have been to have this kind of advice before the trial starts? Pralidoxime is expensive, and high doses might be unaffordable in many places. An affordable pralidoxime preparation should be part of a public-health response to the considerable problem of pesticide poisoning in developing countries.8,9 We believe the drug will save lives,
particularly in places where high-tech equipment is not available and many die simply because a respirator cannot be provided for every patient who needs one.10,11 However, this public-health problem would also be helped by better research support for investigators such as Pawar and colleagues, who should be highly commended for their endeavours. *Peter Eyer, Nicholas Buckley Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Munich D-80336, Germany (PE); South Asian Clinical Toxicology Research Collaboration, Sri Lanka (PE, NB); and Clinical Pharmacology and Toxicology, Canberra Hospital, Canberra, ACT, Australia (NB) [email protected] We declare that we have no conflict of interest. 1
2 3 4
5
6
7 8 9 10
11
Pawar KS, Bhoite RB, Pillay CP, Chavan SC, Malshikare DS, Garad SG. Continuous pralidoxime infusion versus repeated bolus injection to treat organophosphorus pesticide poisoning: a randomised controlled trial. Lancet 2006; 368: 2136–41. Eyer P. The role of oximes in the management of organophosphorus pesticide poisoning. Toxicol Rev 2003; 22: 165–90. Johnson MK, Jacobsen D, Meredith TJ, et al. Evaluation of antidotes for poisoning by organophosphorus pesticides. Emerg Med 2000; 12: 22–37. Eddleston M, Eyer P, Worek F, et al. Differences between organophosphorus insecticides in human self-poisoning: a prospective cohort study. Lancet 2005; 366: 1452–59. European Association of Poisons Centres and Clinical Toxicologists/American Academy of Clinical Toxicology. Position paper: ipecac syrup. J Toxicol Clin Toxicol 2004; 42: 133–43. Schulz KF, Chalmers I, Hayes RJ, Altman DG. Empirical evidence of bias: dimensions of methodological quality associated with estimates of treatment effects in controlled trials. JAMA 1995; 273: 408–12. Schulz KF, Grimes DA. Generation of allocation sequences in randomised trials: chance, not choice. Lancet 2002; 359: 515–19. Buckley NA, Roberts D, Eddleston M. Overcoming apathy in research on organophosphate poisoning. BMJ 2004; 329: 1231–33. Eddleston M. Patterns and problems of deliberate self-poisoning in the developing world. QJM 2000; 93: 715–31. Shivakumar S, Raghavan K, Ishaq RM, Geetha S. Organophosphorus poisoning: a study on the effectiveness of therapy with oximes. J Assoc Phys India 2006; 54: 250–51. Eddleston M, Mohamed F, Davies JO, et al. Respiratory failure in acute organophosphorus pesticide self-poisoning. QJM 2006; 99: 513–22.
DDT: a polluted debate in malaria control A recent press statement from WHO about dichlorodiphenyltrichloroethane (DDT) and indoor residual spraying for malaria control1 caused a considerable stir, despite the fact that, in terms of policy, it merely re-iterated WHO’s endorsement of DDT as a useful insecticide for malaria control, albeit in a highly promotional way. In this recurring debate, arguments for and against DDT, as before, have been heated and mainly based on considerations far removed from the realities of malaria control. www.thelancet.com Vol 368 December 16, 2006
One group that criticised the WHO statement has inferred that my resignation from WHO’s Global Malaria Programme in September, 2006, was related to my opposition to its promotion of DDT.2 This assumption is erroneous. For many years, WHO’s malaria-control professionals have fought hard against pressure from various sides to ensure access in malaria-endemic countries to DDT.3 Hopefully, the statement now issued by the Global Malaria Programme1 will put an end to this debate, so that all countries that need DDT for malaria
Published Online December 7, 2006 DOI:10.1016/S01406736(06)69812-7
2111
Comment
Panos Pictures
The printed journal includes an image merely for illustration
control will have unfettered access to use it in accordance with WHO guidelines and with the Stockholm Convention on Persistent Organic Pollutants, if they are signatories to the latter. Meanwhile, remarks from the opposite camp have not lacked passion, conveying the impression that large-scale use of DDT for malaria control, so long held hostage to misguided concerns for the environment, will now save the lives of millions of people from malaria.4 This idea is not so simple. As pointed out in WHO’s new position statement, indoor residual spraying is an effective intervention, provided a programme infrastructure can be set up and maintained to include trained sprayers, supervisors, managers, stocks, equipment, and vehicles, that roads allow access to every village at the right time at least once a year, and that insecticides are not diverted to agriculture. The need to prevent diversion has been highlighted for DDT, but for malaria control it is equally important for other insecticides. Furthermore, especially in areas with intense and perennial transmission, it is essential to maintain the population’s long-term acceptance of spraying once or several times a year.5 In view of the difficulties encountered in maintaining indoor residual spraying, WHO has invested substantially in exploring other methods, especially insecticide-treated bednets. These nets have been effective in many rigorous trials,6 especially to reduce childhood mortality in Africa. Few trials have compared insecticide-treated nets and indoor residual spraying, but results so far suggest that the methods are more or less equal in efficacy.7 As pointed out by WHO,8 the two methods are similar 2112
in the way they work, although unlike indoor residual spraying, insecticide-treated nets can protect individual users or households. Few data exist for the use and cost-effectiveness of combining these two methods. In view of the substantial costs of prevention for the huge populations at risk, national programmes will generally need to choose one of these two methods for a specific geographical area. The choice of insecticide is secondary. Since only pyrethroids can be used for insecticide-treated nets, and pyrethroid resistance is emerging as a constraint on their effectiveness,9 the fact that four classes of insecticides can be used for indoor residual spraying should be one of the main reasons justifying renewed interest in this method. In the choice between indoor residual spraying and insecticide-treated nets, a WHO study group convened in 2004 noted that the decision should, in most cases, be based on operational factors.8 Because long-lasting insecticidal nets can be managed easily with minimum risk of diversion of insecticide, for most high-burden countries that have not developed an infrastructure for indoor residual spraying, the priority will be to ensure coverage of at-risk populations with such long-lasting nets. The renewed interest in indoor residual spraying could lead to interminable debates in countries about the pros and cons of DDT. Such discussions pit sectors against politicians when, in fact, a non-partisan commitment is needed desperately to protect individuals at risk of malaria with one of the two proven methods. Allan Schapira 1227 Genève-Acacias, Switzerland [email protected] I resigned my post as coordinator, vector control and prevention, of the Global Malaria Programme, WHO, on Sept 6, 2006, because of disagreements with the director of the programme about policy issues. 1
2
3 4
5
WHO. WHO gives indoor use of DDT a clean bill of health for controlling malaria. WHO promotes indoor residual spraying with insecticides as one of three main interventions to fight malaria. Sept 15, 2006: http://www.who. int/mediacentre/news/releases/2006/pr50/en/print.html (accessed Nov 15, 2006). Pesticide Action Network North America. Global coalition of health and toxic experts demand that WHO stop irresponsible promotion of DDT. Sept 26, 2006: http://www.panna.org/resources/newsroom/stopWhoProm otionDdt20060926.dv.html (accessed Nov 15, 2006). Schapira A. DDT still has a role in the fight against malaria. Nature 2004; 432: 439. Stossel J. Hooray for DDT’s life-saving come-back. Oct 4, 2006: http://www. townhall.com/columnists/JohnStossel/2006/10/04/hooray_for_ddts_lifesaving_comeback (accessed Nov 15, 2006). Global Malaria Programme. Indoor residual spraying: use of indoor residual spraying for scaling up global malaria control and elimination. 2006: http://malaria.who.int/docs/IRS-position.pdf (accessed Nov 9, 2006).
www.thelancet.com Vol 368 December 16, 2006
Comment
6 7
Lengeler C. Insecticide-treated bednets and curtains for preventing malaria. Cochrane Database Syst Rev 2004; 2: CD000363. Lengeler C, Sharp B. Indoor residual spraying and insecticide-treated nets. In: Murphy C, Ringheim K, Woldehanna S, Volmink J. eds. Reducing malaria’s burden: evidence of effectiveness for decision makers. Washington, DC: Global Health Council, 2003: 17–24.
8
9
Report of a WHO study group. Malaria vector control and personal protection. 2006: http://www.who.int/malaria/docs/WHO-TRS-936s.pdf (accessed Nov 9, 2006). Etang J, Chandre F, Guillet P, Manga L. Reduced bio-efficacy of permethrin EC impregnated bednets against an Anopheles gambiae strain with oxidasebased pyrethroid tolerance. Malar J 2004; 3: 46.
Art for women’s health The difference in the sexual and reproductive health status of women in developed and developing countries is vast. This disparity represents one of the starkest examples of social injustice of our time. About 530 000 pregnant women and 3 million newborn babies die every year because of complications related to pregnancy and childbirth. Almost all these deaths happen in developing countries.1 Similarly, sexually transmitted infections, reproductive-tract infections, cervical cancer induced by the human papillomavirus, and other gynaecological disorders disproportionately affect the most vulnerable and disenfranchised populations of women. Much could be done to rectify these situations if more people were informed about and mobilised to act towards the improvement of global sexual and reproductive health. Greater advocacy and support for sexual and reproductive health interventions—including information-based campaigns, for example—could lead to substantial changes in the dire conditions many women and their newborn babies currently endure. The intention of the Art for Health project is to contribute to these efforts in an innovative way. Specifically, the project uses contemporary art as a medium to increase people’s awareness of sexual and reproductive health issues around the world, particularly those that negatively affect the lives of women and their families. Participants at the XVIII World Congress of the International Federation of Gynecology and Obstetrics (FIGO)—in Kuala Lumpur, Malaysia, Nov 5–10, 2006— will be able to view the first set of contemporary artworks produced for the Art for Health project at WHO’s stand. The project is actively endorsed by the WHO Department of Reproductive Health and Research (RHR), which has commissioned 18 paintings and is sponsoring the first exhibition of a selection at the congress. The department is also using the artwork for promotional material and publications. The paintings that will be featured at the congress portray women from diverse ethnic and social backwww.thelancet.com Vol 368 December 16, 2006
grounds. Within the images are messages by the women themselves that call on the viewer to join them in a unified effort to better their lives and those of future generations. The statements incorporated into the two representative pieces accompanying this Comment are modifications of famous quotes of outspoken women2 and exemplify these interconnected themes of solidarity, agency, and collective action. “Same sky, same women”, for example, promotes awareness of an underlying tie connecting women around the world (figure 1). “I want to fight with dreams in my soul, with you” furthers this sentiment by asking viewers to engage in partnerships with women living in low-resource nations, partnerships that are characterised by mutual respect and geared
Published Online November 5, 2006 DOI:10.1016/S01406736(06)69642-6
Figure 1: Same sky, same women Elisabetta Farina, 2006, acrylic on canvas.
2113