Tim Allen and Melissa Parker argue that a biosocial approach is necessary for ‘deworming’ to succeed in improving lives

Allen, Tim

Parker, Melissa

LSE Research Online

13.2.2017Debunking Delusions around Dewormingblogs.lse.ac.uk/africaatlse/2017/02/13/debunking-delusions-around-deworming/Tim Allen and Melissa Parker argue that a biosocial approach is necessary for ‘deworming’ to succeed inimproving lives.The term Neglected Tropical Diseases (NTDs) was introduced around 15 years ago and has helped inconcentrating attention on largely-ignored infections. Indeed, it has resulted in what has been hailed as thelargest public health programme ever undertaken. However, the success of the term has created problems,which we have analysed in detail in our paper Neglected Tropical Diseases in Biosocial Perspective. One issueis that the term makes no biological sense. It refers to a wide range of diseases that are very different to oneanother, and which often require very different kinds of treatment.  To use the term as some sort of homogeneouscategory can therefore be misleading. Also, the fact that ‘neglect’ arises from social priorities, social relations andsocial behaviour is commonly set aside. It is neglected people who are typically infected with these diseases;and that kind of neglect has political and economic connotations that cannot be wished away.Photo Credit: Romina Rodríguez Pose/ODI via Flickr (http://bit.ly/2k49P2y) CC BY-NC 2.0In another paper Deworming Delusions? Mass Drug Administration in East African Schools , we discuss theconfusion that arises between the terms ‘mass drug administration for neglected tropic diseases’ and‘deworming’. Both terms involve treatment for particular diseases with tablets and they can, in practice, be thesame; but, the former often refers to treatment for multiple and diverse diseases in a population, while the latteroften refers specifically to the treatment of children for a range of parasitic worms called ‘soil-transmittedhelminths’. This conflation can result in considerable confusion in the academic literature and public debates.Arguments about one are applied to the other, without a careful unpacking of what is being addressed.It is one of several problems with the seminal article by Ted Miguel and Michael Kremer on ‘deworming’ inKenyan schools. Debates about that work are central to the fierce debates that have been described as WormWars. However, a point which is almost always overlooked is that their 2004 article actually deals with treatmentfor both soil-transmitted helminths and a very different kind of disease: bilharzia (schistoma mansoni), and theauthors do not separate the possible effects of treatments with two different drugs in their analysis.Some have observed that deworming has not been demolished, while referring to the work of Macartan1/3Humphries and Chris Blattman. To some extent we agree. No-one – as far as we know – would argue thatheavily-infected people suffering from parasitic infections should not be treated. However, the 2004 paper byMiguel and Kremer on deworming in schools in western Kenya has been given huge status, and is often themain or only cited source of evidence that school-based deworming is effective. A re-study of their data set,which was actually collected as long ago as the late 1990s, has shown that the findings presented in the 2004paper were flawed or wrong. It was this re-study by Alexander Aiken, Calum Davey, James Hargreaves andRichard Hayes that initially triggered the Worm Wars debate.Macartan Humphries’ contribution to the debate is one of the most thoughtful and careful analyses. He isrestrained in the wording of his criticisms of the 2004 Kenyan deworming paper, but a close reading of hisassessment ends up being devastating. He reinforces the points made by Aiken et al, and agrees with them thatthe results reported in 2004 by Miguel and Kremer were unsound.Chris Blattman, who openly acknowledges that he worked with Miguel and Kremer on some of their Kenyandeworming work, does his best to be more supportive of their 2004 paper in a blog post entitled Dear Journalistsand Policymakers: What You Need to Know about Worm Wars, while acknowledging some of the problems withtheir econometrics. But, he does not engage with the findings of other studies, or the wider debates aboutwhether or not school-based deworming in practice is likely to be effective. Chris ends another blog post entitledThe 10 things I learned in the trenches of the Worm Wars  with the following statement: ‘To me, the real tragedy isthat, 18 years after the Kenya deworming experiment (which was not even a real experiment) we do not havelarge-scale, randomized, multi-country, long-term evidence on the health, education, and labour market impactsof deworming medicine. This is not some schmuck cause. This is touted as one of the most promisingdevelopment interventions in human history.’In fact, there are more than 45 other trials evaluating deworming. Some of these have been on a large scale.The results have been analysed in a Cochrane Review (Cochrane Reviews are generally regarded as the ‘GoldStandard’ of medical evidence), and show that deworming programmes have minimal or no positive effects.When the latest version of the Cochrane Review on deworming was published in 2015, the World HealthOrganization’s (WHO) Advisory Group on NTDs took the extraordinary step of setting aside the conclusion. Thismust have been an unprecedented move for a WHO committee. Those associated with the mass dewormingagenda went so far as to argue that the Cochrane Systematic Review methodology is not appropriate forassessing its impact, and that it is of little value in guiding global deworming policy.While there may well be problems with overemphasising evidence from random control studies, the WHOdismissal of the Cochrane Review process is ironic. An important reason why Miguel and Kremer’s 2004 articlehas been given so much prominence is that it has been viewed as replicating the rigour of the random controldesign. Unsurprisingly, therefore, Miguel and Kremer have taken an alternative approach to the CochraneReview. They have tried to show that its conclusions are incorrect. They do this in a new paper: Does MassDeworming Affect Child Nutrition? Meta-analysis, Cost-Effectiveness, and Statistical Power. This draft articlebasically critiques the whole ‘Cochrane Review’ of random control trials dealing with deworming.Croke et al make econometric arguments which Paul Garner and his colleagues of the Cochrane Review willneed to address at some point, but it seems appropriate to make some brief non-technical comments here. In anutshell, Croke et al argue that the Cochrane Review of deworming Random Control Trials is ‘underpowered’,because deworming treatment is so cheap that even if it has a very small overall effect, it is still worth doing. It issuggested that the key question facing policymakers is whether the expected benefits of mass drugadministration of tablets to potentially infected populations without any individual testing exceed the estimatedUS$0.30 per treatment cost.This strikes us as an inherently problematic argument. To begin with, it is not clear where the figure of US$0.30per treatment comes from. The source is given as GiveWell, an organisation which endorses the work ofdeworming charities, but does not do field research. Yet even the figure used by parts of WHO promotingdeworming is US$0.50, and other estimates are well above US$0.60. It depends, in part, on which drugs we aretalking about. Mass drug administration for lymphatic filariasis in Haiti, which targeted 105,750 people, reportedlycost US$2.23 per person.2/3So where is the evidence that mass deworming is being effectively delivered at US$0.30 per person? If there issuch evidence, can it be replicated and up-scaled? Importantly, what are the consequences of chasing thisUS$0.30 target?To do deworming on the cheap implies that funds are not available for some rather important activities. It requiresmost or all of the following:(1) The drugs are indefinitely donated free of charge by pharmaceutical companies;(2) most/all of the costs of transport are excluded;(3) Those distributing the tablets are volunteers and given only the most rudimentary training;(4) The salaries of national staff in Ministries of Health, staff in district offices, staff in medical schools, and staffin international organisations are all excluded from the calculation;(5) There is no significant expenditure on health education, or ‘community’ mobilisation, or the seeking ofparental support;(6) There is no significant expenditure on effective monitoring of whether or not those targeted have actuallyswallowed the tablets, and(7) There is no significant expenditure on monitoring of the social and biological effects of handing out so manymedicines;(8) There is no significant expenditure on vector control or other measures to reduce the rates of reinfection.The problem is that if these things apply and the target for low cost deworming is achieved, the possibility of theprogramme sustainably controlling diseases is unlikely. Interestingly, Miguel and Kremer have themselvesrecognised this in an excellent paper they published in 2007.  Also, with respect to point (8), it is worth notingthat recent research on school-based deworming for soil-transmitted helminths in the same locations of Kenyawhere Miguel and Kremer’s old data set was gathered in the late 1990s, has demonstrated that deworming canbe effective when there is a corresponding improvement in other things, including improved sanitation. Inschools where there have been no such improvements, treated children are almost immediately re-infected.If ‘deworming’ is to be done well and to really change lives for the better, it requires a biosocial approach, drawingon evidence from diverse disciplines. It also requires serious engagement with the impoverished people who areat the receiving end of deworming programmes. No matter how cheap deworming can be made to seemaccording to certain modes of accounting and econometric modelling, if it does not work, then it is still expensive.There are, moreover, ethical concerns that urgently need addressing. A policy that is, in practice, based onteachers and volunteers rounding up thousands of school-age children and making them take tablets withoutparental approval, adequate explanation or any proper monitoring should be as unacceptable in Africa as it is inother parts of the world.Tim Allen is the Head of the Department of International Development at the London School of Economics andPolitical Science and Director of the Firoz Lalji Centre for Africa. Melissa Parker is Professor in MedicalAnthropology at the London School of Hygiene and Tropical Medicine. The views expressed in this post are those of the author and in no way reflect those of the Africa at LSEblog or the London School of Economics and Political Science.3/3

Debunking delusions around deworming

Abstract

Similar works

Full text

Available Versions

LSE Research Online