There is a robust dialog about malaria control ... and some strong opinions. The data to support the opinions is, however, an absolute disgrace.
Hans Herren of the Millennium Institute, Arlington, Virginia and Charles Mbogo of the International Center of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya have written an opinion piece about the position of Roberts and Tren on DDT and malaria ... and I want to add my 2 cents to this conversation.
The text of the Herren and Mbogo article is copied below and is also at http://ehsehplp03.niehs.nih.gov/article/fetchArticle.action;jsessionid=CB9C214F4F08E507568E80E7375EC2D4?articleURI=info:doi/10.1289/ehp.1002279
The Roberts and Tren response, also copied below and at http://www.fightingmalaria.org/article.aspx?id=1470
First the observations of Herren and Mbogo
The Role of DDT in Malaria Control
Citation: Herren HR, Mbogo C 2010. The Role of DDT in Malaria Control. Environ Health Perspect 118:a282-a282. doi:10.1289/ehp.1002279
Online: 01 July 2010
H.R.H. is employed by the Millennium Institute, a nonprofit organization; CM is employed by icipe (International Center for Insect Physiology and Ecology), Nairobi, Kenya.
The letter “DDT and Malaria Control” (Tren and Roberts 2010) is the latest in a long string of opinion pieces placed by authors associated with Africa Fighting Malaria (AFM). Appearing in both the popular media (e.g., AFM 2006; Bate 2009; Bate and De Lorenzo 2007; Roberts 2007a; Tren 2002) and scientific literature (e.g., Attaran et al. 2000; Roberts 2001, 2007b; Roberts et al. 2000, 2004; Tren 2009), these articles and letters reduce the complex issue of malaria control to a single, dichotomous choice between DDT and malaria. Framing the issue in this manner is a dangerous oversimplification and an distraction from the critical dialog on how to effectively combat malaria around the world—particularly in African communities.
The question that AFM and malaria control experts must ask is not “Which is worse, malaria or DDT?” but rather “What are the best tools to deploy for malaria control in a given situation, taking into account the on-the-ground challenges and needs, efficacy, cost, and collateral effects—both positive and negative—to human health and the environment, as well as the uncertainties associated with all these considerations?”
Tren and Roberts (2010) briefly acknowledged that alternatives to DDT exist (while denigrating them as “supposed solutions”), but in typical fashion they focused most of their letter on the chemical, arguing that the health effects of malaria are much worse that those of DDT exposure. As malaria professionals we are well aware of the dire health consequences of malaria, but also of DDT. The challenge before us is therefore to determine how much weight to give to vector control within the broader context of a malaria control program; within vector control, how much weight to allot to nets versus indoor residual spraying (IRS); and within IRS, how much weight to give to DDT or some other chemical.
These decisions are indeed complex and location specific. In this regard, van den Berg’s commentary, “Global Status of DDT and Its Alternatives for Use in Vector Control to Prevent Disease” (van den Berg 2009), is a most useful contribution. In contrast, Tren and Roberts’ (2010) advice that “van den Berg’s concerns should be ignored” strikes us as reckless and irresponsible.
In 2006, Allan Schapira, former coordinator of vector control and prevention of World Health Organization’s Global Malaria Programme, observed that malaria control discussions had become “polluted,” and warned, “The renewed interest in indoor residual spraying could lead to interminable debates in countries about the pros and cons of DDT” (Schapira 2006). However well intentioned, Tren and Roberts (2010)—as with much of AFM’s output—do more to fuel those “interminable debates” than to meaningfully inform decisions that will save people’s lives.
Africa Fighting Malaria 2006. MedicalNewsToday.com 18 July. Africa Fighting Malaria Responds To Berkeley University Study Into DDT And Neurodevelopment In Children. Available: http://www.medicalnewstoday.com/articles/47470.php [accessed 11 March 2010].
Attaran A, Roberts DR, Curtis CF, Kilama WL 2000. Balancing risks on the backs of the poor. Nat Med 6: 729–731. FIND THIS ARTICLE ONLINE
Bate R 2009. Joy Online (Ghana), 29 May. Comment: UN disarms Weapon of Malarial Destruction. Available: http://news.myjoyonline.com/features/200905/30279.asp [accessed 11 March 2010].
Bate R, De Lorenzo M 2007. New Times (Rwanda) 10 January. Reconsider DDT against Malaria. Available: http://www.aei.org/article/25431 [accessed 11 March 2010].
Roberts DR 2001. DDT risk assessments. Environ Health Perspect 109: A302–A303. FIND THIS ARTICLE ONLINE
Roberts DR 2007a. New York Times, August 20. A New Home for DDT. Available: http://www.nytimes.com/2007/08/20/opinion/20roberts.html [accessed 11 March 2010].
Roberts DR 2007b. Preventing malaria in endemic areas [Editorial]. BMJ. (335): pp. 1001–1002. doi:10.1136/bmj.
39370.673785.BE [Online 24 October 2007].
Roberts D, Curtis C, Tren R, Sharp B, Shiff C, Bate R. 2004. Malaria control and public health. Emerg Infect Dis 10: 1170–1171. Available: http://www.cdc.gov/ncidod/EID/vol10no6/03-0787_03-1116.htm [accessed 11 March 2010].
Roberts DR, Manguin S, Mouchet J 2000. DDT house spraying and re-emerging malaria. Lancet 356: 330–332. FIND THIS ARTICLE ONLINE
Schapira A. 2006. DDT: a polluted debate in malaria control. Lancet 368: 2111–2113.; doi: 10.1016/S0140-6736(06)69812-7 FIND THIS ARTICLE ONLINE
Tren R 2002. New York Times, 28 December. Africa needs DDT [Letter]. Available: http://www.nytimes.com/2002/12/28/opinion/l-africa-needs-ddt-590258.html [accessed 11 March 2010].
Tren R. 2009. Insecticides for public health. CMAJ 180: 784.; doi:.10.1503/cmaj.090358 FIND THIS ARTICLE ONLINE
Tren R, Roberts D. 2010. DDT and malaria prevention. Environ Health Perspect 118: A14–A15.; doi: 10.1289/ehp.0901276 FIND THIS ARTICLE ONLINE
van den Berg H. 2009. Global status of DDT and its alternatives for use in vector control to prevent disease. Environ Health Perspect 117: 1656–1663.; doi: 10.1289/ehp.0900785
And now the response of Roberts and Tren. I should note that I am quite well acquainted with the work of all the participants in this dialog and have some respect for their work. I would observe that there is a tremendous frustration that questions that should be easy to answer are still being talked about at the opinion level and not at the more interesting and important "fact" level ... but this should come as no surprise given my interest in cost accounting facts!
DDT in Malaria Control: Roberts and Tren Respond
Donald Roberts & Richard Tren | 01 Jul 2010
Environmental Health Perspectives
[Environmental Health Perspectives continues the debate on DDT's role in malaria control. Herren & Mbogo respond to AFM's Roberts and Tren letter commenting on a paper published in 2009 by van den Berg. Roberts and Tren in turn respond below to Herren & Mbogo's letter, defending their work to protect the use of DDT in malaria control, and warn that as pressure mounts to eliminate all uses of DDT without a true replacement, the debates will become more polemic in nature.]
Herren and Mbogo's critique of our response (Tren and Roberts 2010) to van den Berg (2009) is lacking in substance. In their letter, they attack our work by characterizing our advocacy for using DDT to control malaria as a distraction from larger malaria control issues. These authors apparently discount the fact that some African countries are presently making highly effective use of DDT to reduce both malaria deaths and malaria infections. Countries that use DDT benefit from its spatial repellent action that stops mosquitoes from entering houses and transmitting disease, and no alternative insecticide does this (Roberts and Tren 2010). In addition, Herren and Mbogo apparently do not understand that our advocacy is consistent with that exhibited by the malaria control community, with hundreds signing a petition to prevent DDT elimination through Stockholm Convention negotiations. If DDT had been eliminated, countries presently using DDT would have been deprived of its benefits for protecting health and saving lives. Herren and Mbogo claim that our response to van den Berg's commentary (van den Berg 2009) was fixated on DDT, in lieu of addressing the larger issues of what should be done to control malaria. In our letter (Roberts and Tren 2010), we addressed what we considered to be an attack on DDT use. How could we have responded without addressing the issues in van den Berg's commentary?
Herren and Mbogo mischaracterize our position vis-à-vis DDT and alternative insecticides by asserting that we are reducing the malaria control debate to a simplistic equation of malaria or DDT. In fact, we have a public record of supporting the use of insecticide-treated nets and the use of alternative insecticides for malaria control. However, we have repeatedly emphasized that, for obvious reasons, insecticide-treated nets are not the only solution for malaria control. In fact, we object to a theme of nets and nets alone as much as we would object to a theme of DDT and DDT alone. Basically, there is no single-solution approach to malaria control. All tools are needed—not just those that are currently in vogue.
Herren and Mbogo state that they are fully aware that malaria is a worse outcome than possible health effects of DDT. We agree with them and appreciate their willingness to admit this, because their admission opposes published speculations that DDT might be causing more harm than good (Chen and Rogan 2003).
Herren and Mbogo conclude that we "do more to fuel those 'interminable debates' [DDT or no DDT for malaria control] than to meaningfully inform decisions that will save people's lives." It seems that these authors ignore the fundamental fact that we do not elaborate on alternative approaches to malaria control because the alternatives are not presently under threat of elimination. The alternatives are being used and should continue to be used, but the future is far less certain for DDT. Advocacy saved DDT from being eliminated during the original negotiations for the Stockholm Convention, and lives are being saved and diseases prevented as a consequence. The idea that the threat is over and that DDT is now available to those countries making effective use of it is wrong. The Stockholm Convention Secretariat is now planning to stop all production of DDT in 2017 and eliminate it entirely from use in malaria control programs in 2020 (UN Environment Program 2010). The Stockholm Convention Secretariat plans to prevent future uses of DDT, even though there is no cost-effective replacement for DDT. Given these circumstances, Herren and Mbogo should expect the interminable debates to become even more polemic in the future.
As for the big issues of what should be done to control malaria, our position is clear: Decisions should be based on scientific evidence of what actually works, on local circumstances, and on what proves to be the most cost-effective in terms of reducing disease and preventing human deaths.
My takeaway from this dialog is very simple ... why is it that this is a dialog about opinion and not a reasonable dialog about facts. From my perspective as an accountant, the scientific community is spending far too much time trying to get important conclusions from very weak data ... something that would be intolerable in corporate accountancy, but is the norm in the international relief and development assistance world where millions of dollars are wasted because there is little or no accounting and accountability.
I am a former cost accountant ... and I want to know some very simple facts about malaria control interventions. In any community I want to know these simple facts (1) the mosquito and malaria situation at time A is thus and so; (2) the mosquito and malaria situation at time B is this and so; and, (3) in between time A and time B the following interventions were carried out and they cost thus and so. This is very basic cost and performance accounting ... and would tell the managers of billions of dollars of malaria intervention money whether or not they were getting reasonable impact for their money.
People like Admiral Ziemer of PMI have expressed the need ... and PMI's commitment to meaningful metrics about malaria control performance ... but the ugly fact is that none of the participants in this huge malaria control industry seem to be very interested in getting performance facts into the public space. In my early audit career ... when you cannot get basic information, you know you have a problem that needs to be addressed!
I have read hundreds of pages of scientific paperwork about malaria control ... and it is very clear that the scientists are not addressing the cost and performance matter in a serious way. If they were I am fairly certain that they would find that some sets of interventions are an order of magnitude better than others ... and they would be faced with the troubling fact that there is no chemical or etymological reason that they can identify ... but, I would argue that this "management information" would be enough to help improve decision making about allocation of resources in a very meaningful way.
I am hopeful that one day in the not too distant future people who have big responsibilities in the international official relief and development world will recognize how much scarce resource is being wasted for no other reason than the totally dysfunctional management information dataflows that they have accepted for years!
There is nothing here that I have not said many times before in different ways ... but soon I believe there will be paradigm change in the way socio-economic progress and performance is being managed!