26363 School Deworming at a glance Worms infect more than one third of the world's There is no need to examine each child for the population, with the most intense infections in presence of worms. Individual screening offers no children and the poor. In the poorest countries, safety benefits. And it is not cost-effective; it costs children are likely to be infected from the time they four to ten times more than the treatment itself. stop breast-feeding, and to be continually infected Regular deworming will help children avoid the worst and re-infected for the rest of their lives. Only rarely effects of infection even if there is no improvement in does infection have acute consequences for children. sanitation. Instead, the infection is long-term and chronic, and can negatively affect all aspects of a child's develop- Why deworm in schools? ment: health, nutrition, cognitive development, learn- School-age children typically have the highest ing and educational access and achievement. intensity of worm infection of any age group. In Deworming is safe, easy and cheap addition, the most cost-effective way to deliver deworming pills regularly to children is through All the common worm infections in school-age schools because schools offer a readily available, children can be treated effectively with two single- extensive and sustained infrastructure with a skilled dose pills: one for all the common intestinal worms workforce that is in close contact with the community. (hookworms, roundworms, and whipworms) and the other for schistosomiasis (bilharzia).1 The treatment is With support from the local health system, teachers safe, even when given to uninfected children. can deliver the drugs safely. Teachers need only a few hours training to understand the rationale for The most commonly used drugs for the treatment of deworming, and to learn how to give out the pills common intestinal worms are albendazole (400 mg) and keep a record of their distribution. or mebendazole (500 mg). They are administered as a single tablet to all children, regardless of size or Regular deworming contributes to good health and age. One pill can cost as little as US$0.02 and only nutrition for children of school age, which in turn in the most highly infected communities is treatment leads to increased enrolment and attendance, required more than once a year. reduced class repetition, and increased educational attainment. The most disadvantaged children ­ such Praziquantel, the drug of choice to treat schistosomia- as girls and the poor ­ often suffer most from ill sis, is slightly more expensive ­ on average US$0.20 health and malnutrition, and gain the most benefit per treatment for a school aged child. Treatment once from deworming. a year is sufficient even in the most infected communi- ties. Praziquantel is given as a single dose, but the School-based deworming has its full impact when number of pills has to be adjusted to the size of the delivered within an integrated school health child. The preferred method for schoolchildren is an program that includes the following key elements inexpensive "dose-pole" that uses the height of the of the FRESH (Focus Resources on Effective School child to estimate the dosage. Health) framework:2 Deworming pills are heat-stable and require no cold 1. Health policies in schools that advocate the role of chain for delivery. With a shelf life of up to four teachers in health promotion and delivery; years, they can be purchased in bulk to reduce costs 2. Adequate sanitation and access to safe water and to ensure uninterrupted supply. to reduce worm transmission in the school In communities where infection is common all children environment; should be offered treatment. The need for mass treat- 3. Skills-based health education that promotes good ment of schoolchildren can be determined by simple hygiene to avoid worm infection; and low cost survey techniques that identify whether 4. Basic health and nutrition services that include reg- the school is in an area of significant risk of infection. ular deworming. 1 Any one of the following can be used to treat common intestinal 2 For further information about the school health program activities worms: albendazole, mebendazole, levamisole or pyrantel. The and the FRESH framework, please consult School Health at a drug of choice for the treatment of schistosomiasis is praziquantel. glance, World Bank. November 2003 How to get started? 1. Determine whether the school is at risk of infection · Explain that heavily infected children may experience mild side effects when the treatment · WHO, with its partners, keeps track of expels their worms, and that the complaints of epidemiological information on the distribution one child often trigger other schoolchildren to of worm infection for most countries, and uses claim similar symptoms. GIS technology to develop maps indicating the areas at risk of infection. If the target 4. Procure drugs and materials school is located in one of these areas then mass treatment is indicated. · Use established systems, such as national pharmacies, to procure drugs of assured · If information is not available, use WHO quality. Involve the health services in the guidelines to conduct a rapid epidemiological proper storage of drugs in health clinics, and assessment to determine whether the school is in delivery to schools. In addition to the pills, in an area of high prevalence of infection. stationery for record keeping and a dose pole for the administration of praziquantel are all 2. Determine the strategy for mass treatment based that is required to deliver treatment in schools. on WHO recommendations 5. Treat children · Treatment should be offered to all children in schools where more than half the children are · Schools and health personnel should work believed to be infected with intestinal worms or together to decide on a treatment day for where any child passes blood in their urine as delivering deworming and the other health a result of schistosomiasis. Treatment should be and nutrition services of the FRESH package. offered at least once each year for intestinal Health personnel should be aware of any worms and at least every two years for schisto- drug distribution by teachers, and should be somiasis. If infection is particularly common, ready to provide support and supervision for the frequency of treatment may be increased to any side effects. twice a year for intestinal worms and once a year for schistosomiasis. 6. Monitoring and Evaluation · Other schools should not require routine · Routine monitoring of deworming involves the treatment programs; instead children should recording of basic process indicators: the be encouraged to seek treatment at a health number (or %) of children treated and the center if they suspect they are infected. One quantity of drugs used. This assists in routine important exception is if the school is in an planning, and also helps reduce inappropriate area of low (less than 10%) but persistent use of drugs. If a more detailed evaluation is schistosomiasis infection, in which case required, the program impact can be assessed children should be offered treatment twice by an epidemiological survey. during their primary schooling: once at entry, and once when leaving school. · Individual diagnosis has no role in school- based mass treatment programs. It is Contact wormcontrol@who.int to obtain: complicated, and it is neither cost-effective nor necessary as the treatment is safe even 1. WHO Expert Committee Reports for those children who are uninfected. 2. WHO Guidelines for Managers of School 3. Train teachers and inform the community Health Programs · Train teachers to understand the benefits of 3. WHO Partners for Parasite Control data deworming in schools, and to distribute the base of country maps pills and keep records. A group of 40-50 teachers can be trained in less than one day. 4. Deworming and health education training materials · Communicate with parents, community leaders and local health agents about the objectives of the deworming in schools and what they should expect. Evidence that school deworming is beneficial and cost-effective Deworming contributes to Education for All schooling was gained for an investment of US$4 in Studies in low-income countries of Africa, South deworming, as compared to US$38 to US$99 for other America and Asia confirm that children with intense interventions. [4] The Rockefeller hookworm control pro- worm infections perform poorly in learning ability tests, gram early in the 20th century in the Southern USA cognitive function and educational achievement. Differ- achieved a similar reduction in absenteeism (23%) and ences in test performance equivalent to a six- month long-run effects on labor income suggest the benefit of a delay in development can typically be attributed to hookworm-free childhood to be around 45% of adult heavier infections of the sort experienced by around 60 wages [6]. Deworming is therefore an efficient invest- million school age children [1]. Absenteeism is more fre- ment in human capital. quent among infected than uninfected children: the Deworming has major externalities for untreated heavier the intensity of infection, the greater the absen- children and the whole community teeism, to the extent that some infected children attend By reducing the transmission of infection in the school half as much as their uninfected peers [2]. community as a whole, deworming substantially Deworming can benefit children's learning [3] and sub- improves health and school participation for both stantially increase primary school attendance and signif- treated and untreated children, in treatment schools and icantly increase a child's ability to learn in school [4]. in neighboring schools. As a result, treating only school Deworming is an exceptionally low cost intervention age children can reduce the total burden of disease due Operational research in Ghana and Tanzania has to intestinal worm infections by 70% in the community demonstrated that for the first five years of intervention, as a whole [7]. These externalities are large enough to the average yearly cost of delivered treatment ­ taking justify fully subsidizing treatment. They also explain why into account current drug prices ­ is typically less than deworming is beneficial even without improvements in US$0.50 per child in an area where both schistosomia- sanitation. sis and the common intestinal worms are present, and Deworming targets one of the most common, long-term less than US$0.25 per child in an area where only the infections of children in low-income countries. latter are present. This is the total cost which includes For girls and boys aged 5 to 14 years in low-income training of teachers, as well as the procurement and dis- countries, intestinal worms account for an estimated 11 tribution of drugs to students [5]. and 12 percent, respectively, of the total disease Deworming gives a high return to education and burden, and represent the single largest contributor to labor income the disease burden of this group. An estimated 20 per- A randomized evaluation of school-based mass cent of disability adjusted life years lost because of com- deworming for schistosomiasis and intestinal worms in municable disease among school children is a direct Kenya found that absenteeism was reduced by one- result of intestinal worms. quarter. Deworming was the most cost-effective method The table shows the global number of cases and preva- of improving school participation among a series of lence of major worm infections among educational interventions. An extra year of primary school-age children. Infection Number of Cases (millions) Prevalence Roundworm (Ascaris) 320 35% Whipworm (Trichuris) 233 25% Hookworm (Necator/Ancylostoma) 239 26% Schistosoma haematobium 56 (Africa only) 33.3% (Africa only) Schistosoma mansoni 25 (Africa only) 16.4% (Africa only) Sources: Bundy, D.A.P. et al. (1997) Intestinal nematode infections, in Health Priorities and Burden of Disease Analysis: Methods and Applications from Global, National and Sub-national Studies (Murray, C.J.L. and Lopez, A.D., eds), Harvard University Press for the World Health Organization and the World Bank. Van der Werf, M.J. et al. (2003) Quantification of clinical morbidity associated with schistosome infection in sub-Saharan Africa. Acta Tropica (in press). References: 1. Partnership for Child Development. Heavy schistosomiasis associated with poor short-term memory and slower reaction times in Tanzanian schoolchildren. Tropical Medicine and International Health, 2002, 7:104-117. 2. Nokes C, Bundy D. Compliance and absenteeism in schoolchildren: implications for helminth control. Transactions of the Royal Society of Tropical Medicine and Hygien,1993, 87:148-1521. 3. Grigorenko, E., Sternberg, R., Ngorosho, D., Nokes, C., Jukes, M., & Bundy, D. (submitted). Effects of Antiparasitic Treatment on Dynamically-Assessed Cognitive Skills. 4. Miguel E. & Kremer M. (2002) Worms: Identifying Impacts on Health and Education in the Presence of Treatment Externalities. http://post.economics.har- vard.edu/faculty/kremer/ . 5. Partnership for Child Development. The cost of large-scale school health programmes which deliver anthelmintics to children in Ghana and Tanzania. Acta Tropica, 1999, 73: 183-204. 6. Bleakley, H (2002) Disease and Development: Evidence from hookworm eradication in the American South. Report of the Rockefeller Sanitary Commission. http://web.mit.edu/hoyt. 7. Bundy DAP, Wong MS, Lewis LL & Horton J. Control of geohelminths by delivery of targeted chemotherapy through schools. Transactions of the Royal Society of Tropical Medicine and Hygiene, 1990, 84: 115-120. Do's and don'ts in school deworming Key references Do... Prevention and control of schistosomiasis and soil-trans- Do make deworming an integral component of a school mitted helminthiasis. Report of a WHO Expert health program using the FRESH framework. Combine Committee. World Health Organization, Geneva, 2002 deworming with iron and other micronutrient supple- (WHO Technical Report Series, No. 912). ments. Do ensure that teachers and health agents work Helminth control in school-age children. A guide for together at all stages of the program and identify their managers of control programmes. ISBN 92 4 154556 different roles. 9, World Health Organization, Geneva, 2002. Do help teachers understand the benefits of deworm- ing, so that they are supportive and recognize that their The FRESH Toolkit, Focusing Resources on Effective investment of time in deworming is an important contri- School Health. World Bank, Washington DC, 2002. bution to education. Do ensure that local health personnel make careful School Health at a glance, World Bank, Washington plans to manage possible side effects. Improper DC, 2002. management of side effects can ruin the future of the program. The Partnership for Child Development. Better Health, Do make sure that treatment is provided for both intes- nutrition and education for the school-aged child. tinal worms and schistosomiasis where needed. Leading article, Transactions of the Royal Society of Effective deworming requires both treatments. Tropical Medicine and Hygiene, 1997, 91: 1-2. Do make sure that treatment is given regularly and sus- tained. Montresor A et al. Development and validation of a `tablet pole' for the administration of praziquantel in Do protect children throughout their development by sub-Saharan Africa. Transactions of the Royal Society of starting treatment early (e.g. with Early Child Tropical Medicine and Hygiene, 2001, 95:542-544. Development programs) and continuing treatment throughout primary school. The "Partners for Parasite Control": PPC Newsletter Do reach out to non-enrolled school aged children. This (www.who.int/wormcontrol) not only enhances the public health impact of your inter- vention, but also encourages children, especially girls, to attend school. Web sites Don't... www.who.int/wormcontrol Don't waste time and resources trying to examine each www.unicef.org school or child. Deworming drugs are safe and can be www.schoolsandhealth.org given to uninfected children. No individual diagnosis, www.sci.org or assessment of each school is needed. www.worldbank.org Don't exclude adolescent girls from systematic treatment. The drugs are safe, even in pregnancy. For further information, please contact Don Bundy Don't be afraid to give a single dose tablet of at eservice@worldbank.org or Lorenzo Savioli at worm- albendazole or mebendazole even to children of small control@who.int stature. The pills are safe for children over 1 year of age, regardless of their size or weight. Don't hesitate to use a dose pole instead of a scale to decide the appropriate dose of praziquantel. It accu- rately calculates the dosages for school age children and may ­ in the long- term ­ be more reliable than deteriorating scales. Don't wait for sanitation to improve before starting deworming ­ regular treatment will help all children avoid the worst effects of infection. Expanded versions of the "at a glance" series, with e-linkages to resources and more information, are available on the World Bank Health-Nutrition-Population web site: www.worldbank.org/hnp