Global Health Policy
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February 20, 2008
The Wisest Investment We Can Make: Using Schools to Fight Neglected Tropical Diseases
Posted by Michael Kremer at 05:49 PM
Today's pledge by President Bush to invest $350 million in fighting Neglected Tropical Diseases (NTDs) over the next 5 years is one of the wisest investments we can make in combating poverty around the world. This is particularly true when children are mass treated for common diseases through schools. While development initiatives are often driven by sentiment, school based treatment of neglected diseases is backed by rigorous evidence.
Over 400 million school-aged children are infected with parasitic worms (schistosomiasis and soil transmitted helminthes - two of Bush's neglected diseases) which leave them anemic and listless, and so they often skip school or find it hard to concentrate. Yet they can be treated with safe effective drugs for just 50 cents per year per child. Indeed, the evidence shows that mass treatment for these neglected diseases is both the most cost effective way to increase school participation of any intervention yet rigorously tested and one of the world’s most cost effective ways to improve health. These health and education benefits can have long run benefits on productivity and earnings.
Edward Miguel of UC Berkeley and I evaluated the impact of a school-based treatment program run by International Child Support Kenya (ICS). Due to administrative and financial constraints ICS randomly phased the program into schools over several years, providing the opportunity to rigorously evaluate the impact - much as in the randomized trials used in medicine. We found that treatment cut absenteeism from school by 25 percent. This means that children who attend primary school with regular deworming every six months end up receiving the equivalent of one additional year of education. With the higher incomes associated with more education, we estimate that for every dollar spent on deworming, society gains more than $30.
Very similar effects were found by Hoyt Bleakley of the University of Chicago's Graduate School of Business in his careful analysis of the impact of a Rockefeller-funded program that treated the same parasitic worms in the US South at the beginning of the 20th century (also see this article in the Chicago Tribune). As in Kenya, schooling went up. Bleakley traced the effect through to increases in productivity and wages in the areas that had been hardest hit by the worms before treatment, and estimates that 20 percent of the large gap in incomes between the northern and southern states of the US at the time was due to worm infections.
We now have the opportunity to have a similar positive impact on the lives of the poorest children and their communities around the world.
To maximize the impact of the funds, it is important to first target the most cost-effective delivery approaches. First and foremost, that is mass treatment through schools. The reason that school based treatment is key is simple. Children have by far the highest infection rates and the vast majority of children, even in Africa, now go to primary school. Schools collect large numbers of children in one place where they can easily, quickly and safely be treated en masse by teachers with some very basic training. The necessary drugs are cheap and safe - typically pennies per dose - while diagnosis is expensive, so in environments where worms are common, the WHO recommends school-based mass deworming without individual testing. Delivery through clinics is harder because in many areas worm infection is so widespread that most people consider it normal and don’t go to a clinic to be treated. Moreover, heath providers in many developing countries have very high absenteeism rates. Drug deliveries to schools can be made along with books, exams, or other teaching materials, reducing transportation costs. And programs can capitalize on existing administrative infrastructure at the Ministries of Education and Health to maintain low running costs. School-based treatment organized through Ministries of Education can cut costs by more than a third relative to sending out specialist medical teams to move from school to school treating children.
Bush and his administration are not the only people responding to the evidence. While the World Health Organization, the World Bank and groups like Partnership for Child Development, the Schistosomiasis Control Initiative and the Global Network for Neglected Tropical Diseases have been promoting deworming for many years, the evidence on its important impact on education is prompting more Ministries of Education to take note. Madagascar is working on a nation-wide school based program. Zambia, with support from USAID, is planning a large school based program, as is Kenya. The World Economic Forum's Young Global Leaders, of which I am a part, launched an initiative to promote school based mass treatment of parasitic worms under the banner of "Deworm the World."
For less than $300 million a year we could treat all 400 million school aged children who are infected with parasitic worms - if we do this through schools. If the rest of the G8 respond to Bush's call to join him in this initiative we could indeed deworm the world.
Additional information about the impact of investing in fighting soil transmitted helminthes and schistosomiasis can be found through the MIT Poverty Action Lab's Policy Briefcase (.pdf)
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Comments
Michael Kremer’s post has rightly emphasized the importance of deworming and the demonstrable impact that the use of schools as an entry point provides for the sustained distribution of very cheap drugs for the control of both soil transmitted helminths and schistosomiasis. This approach has been endorsed by international organizations, academic research and implemented by NGDO’s for several years. However, what the blog does not refer to is the massive impact of the Global Programme for the Elimination of Lymphatic Filariasis (GAELF) and the African Programme for Onchocerciasis Control (APOC) and the OEPA programme in the Americas.
These programmes benefit from the drug donations of albendazole by GlaxoSmithKline (GSK) and of Mectizan (ivermectin) by Merck & Co. Inc., the two most valuable and efficacious anthelminthic products. The programmes aim respectively to eliminate transmission of lymphatic filariasis globally by 2020 and eliminate transmission of onchocerciasis in the Americas (OEPA) and create in Africa through APOC a sustainable Mectizan distribution program. These programs have been remarkably successful through Community Directed Treatment (CDT) approaches. In 2006, more than 60 million people in 19 countries were reached through the APOC network and 258 million treatments for filariasis were delivered in 44 countries in 2006.
These programs are stopping transmission of these important diseases which fall under President Bush’s initiative, and it is surely the success of APOC and GAELF, plus the International Trachoma Initiative (ITI) and the Schistosomiasis Control Initiative (SCI), which is the evidence base for the new NTD initiative. Importantly these programs provide deworming to these vast populations many of whom are not in reach of any school education let alone health care. They reach the poorest of the poor who have no access to formal health or education sectors. The creation of sustainable drug distribution systems is essential, be it through communities where free drugs are delivered annually or through school-based deworming. These programs are now also working together through the Global Network for Neglected Tropical Diseases to integrate their interventions for improved efficacy.
What the President’s initiative does is recognize the efforts towards integration, and gives the opportunity for expanding existing programmes and creating huge leverage of donated products which are already stopping transmission of filariasis and onchocerciasis but bringing massive ancillary benefits in reducing anemia, deworming and eliminating scabies. The evaluation of the existing filariasis disease programmes in Haiti, Zanzibar, Sri Lanka, Malawi and Uganda have already demonstrated the deworming achieved through the use of albendazole and Mectizan in the African countries evaluated. We also have recent evidence from Zanzibar that the three drugs (albendazole, Mectizan and praziquantel) together can be given without serious adverse events being recorded and that distribution of bednets was increased nine-fold in Nigeria when linked to drug distribution for LF and onchocerciasis. It is essential that the lessons learned from all existing programs to control or eliminate the NTDs are evaluated in seeking to help the targeted poorest populations. It is not only the school-based approach which is necessary as the World Health Organisation has pointed out; there are merits in every delivery mechanism which benefit the poorest. The critical response to this massive opportunity is the recognition that one size does not fit all and that existing donations programs provide probably the most effective platform for cost effective and sustainable delivery of donated drugs.
-David Molyneux, Executive Secretary of the Executive Group of the Global Alliance to Eliminate Lymphatic Filariasis and President of the Royal Society of Tropical Medicine and Hygiene
Posted by: David Molyneux at February 25, 2008 10:33 AM
The above discussion suggests that several approaches have a role to play in the control of neglected tropical diseases. For a collection of diseases prevalent in a wide variety of contexts one size cannot fit all. There are horses for courses and it is worth being clear about the courses for which the school health program is the horse to back.
First, school health programs are effective where the vast majority of children are enrolled in school or have access to a primary school. This is increasingly the case in most regions of the world. In such cases, the reach of the education infrastructure greatly exceeds that of health centres or mobile teams based in urban centres and has the potential to serve the poor rural communities who are most in need. The extensive and equitable coverage of the education system combines with the cost-saving and sustainability implications of school-based drug distribution to make this the delivery mechanism of choice for school children across much of the world.
Second, school health programs are particularly effective where the disease burden is greatest among school children. Infections with worms such as schistosomiasis and hookworm are heaviest among school children and thus have the greatest impact on health in this age-group. However, the focus on health underestimates the burden of disease. Many neglected tropical diseases, including most helminth infections, have an insidious and persistent effect on children's cognitive abilities and their educational potential. Treating these diseases is one of the most cost-effective and pro-poor investments that can be made in children's education.
School health programs recognize that tropical diseases pose a problem for children's education and the education system can be part of the solution. Where children go to school and bear a significant burden of disease, school health programs are the best investment one can make in their health and their education.
-Matthew Jukes, Assistant Professor of International Education, Harvard Graduate School of Education
Ref: Jukes, M. C. H, Drake, L. J., and Bundy, D. A P (2008). School health, nutrition and Education for All. Levelling the Playing Field. CAB International. Wallingford.
Posted by: Matthew Jukes at March 2, 2008 06:18 PM
Response to David Molyneux
Free drugs would certainly help in the global effort to deworm the world. In his response to my post, David Molyneux rightly notes the important role that such subsidies play in programs addressing lymphatic filariasis and onchocerciasis, two of the neglected tropical diseases covered by the new Bush initiative. Ted Miguel (of UC Berkeley) and I concluded from our study in Kenya that long-term subsidies are equally important for programs treating soil-transmitted helminths (STHs) and schistosomes, two of the other diseases covered by the initiative. We found that several “sustainable” approaches to worm control, including cost-recovery from beneficiaries, were ineffective at combating worms relative to the provision of free deworming drugs.
The reason for this is simple: Many of the benefits of taking the drugs spill over to others in the community, so private valuation is understandably low. These positive treatment externalities provide a compelling economic rationale for long-term funding commitments to such programs. The multi-decade commitment of the World Bank and pharmaceutical companies to subsidizing the eradication of onchocerciasis should set an example for the types of long-term commitments required for the elimination of other neglected diseases, such as STHs and schistosomiasis.
But, the issue of whether drugs are donated or purchased has become secondary to ensuring that delivery costs are as low as possible. Since the drugs are cheap, delivery has become the more costly component of many deworming programs, and the choice of delivery mechanism can determine just how cost-effective a program can be.
For the most common and widespread worms – STHs and schistosomes – you get the most bang for your buck by delivering mass treatment through schools. In most parts of the world, the vast majority of primary school aged children are in school. True, you cannot reach every person at risk of infection through schools. But, you do reach a critical mass of the individuals most vulnerable to, and most likely to spread, the disease. Further, school-based drug distribution can be structured in a way that makes it possible for both out-of-school children and adults to participate; for example, by inviting them to school on mass treatment days.
But, there are some crucial differences between the worms in my study and the worms discussed in David Molyneux’s post: Lymphatic filariasis and onchocerciasis are both more severe symptomatically and affect significantly fewer people globally. For example, the global DALY burden for just one of the STHs – hookworm – is close to four times that for lymphatic filariasis and over 40 times that for onchocerciasis (see Hotez et al. 2006, 577), despite the severity of the latter.
What this means, in practice, is that it may make more sense to attack these rarer but more serious worms very intensively in areas where they are common, such as through a community approach. For worms that affect many people in many countries, such as soil-transmitted helminth and schistosomiasis, you can reach far more people over a wide geographic region with limited resources using a school-based delivery mechanism. Where appropriate, alongside this school-based distribution, drug distributors and other community-based mechanisms could be used to reach at-risk populations unreachable through schools.
Leaders throughout the developed world should match President Bush’s pledge of hundreds of millions of dollars in the effort to deworm the world. In those areas where LF and onchocerciasis are common, it makes sense to continue to use a more resource intensive delivery strategy due to the severity of these diseases. However, in the many areas where these diseases are not common, but STH and schistosomiasis are, the impact of the limited resources devoted to fighting these diseases can be maximized by first working to scale-up school-based delivery. Right now, only 10% of children who should be reached are being reached, and reaching the children who are not currently being reached should be a priority.
Citation: Hotez, Peter J., David H. Molyneux, Alan Fenwick, Eric Ottesen, Sonia Ehrlich Sachs, and Jeffrey D. Sachs, Incorporating a Rapid-Impact Package for Neglected Tropical Diseases with Programs for HIV/AIDS, Tuberculosis, and Malaria. PLoS Medicine, 2006. 3(5): 576-584.
Posted by: Michael Kremer at March 20, 2008 12:21 PM