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National Deworming Day 2016
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The Problem: Parasitic Worms


The Problem: Parasitic Worms

More than 868 million children are at risk of parasitic worm infections worldwide.

“A significant body of evidence shows that deworming works to improve children’s health, well-being, education, and long-term economic future.
— World Health Organization. (2016). WHO PCT Databank: Soil-transmitted Helminth Infections.

While virtually nonexistent and unheard of in developed countries today, parasitic worm infections are endemic in many of the poorest countries in the world.

These infections, known as soil-transmitted helminths (STH) and schistosomiasis, interfere with nutrient uptake and can lead to anemia, malnourishment, and impaired mental and physical development. They pose a serious threat to children’s long-term health, education, and productivity. Infected children are often too sick or tired to concentrate at school, or to attend at all.

Worm infections disproportionately affect the poor. They are easily transmitted in areas with poor sanitation and open defecation. Children are particularly susceptible to infection and experience the greatest morbidity.

Parasitic worms exact an enormous toll on human capital, slowing economic development in parts of the world that can least afford it.

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The Solution: A Simple Treatment

The Solution: A Simple Treatment


To combat worm infection, regular treatment with a simple pill is universally recognized as a safe and effective solution. The Deworm the World Initiative supports school-based deworming: treatment delivered through existing education infrastructure, administered by teachers with support from the health system. This approach is highly cost-effective, well accepted by communities, and efficiently targets the population group at greatest risk for infection: children.

Rigorous evidence shows that school-based deworming can improve children’s health, education, and long-term productivity at an average cost of less than $0.50 per child per year.


The Abdul Latif Jameel Poverty Action Lab at MIT lists mass school-based deworming as a “best buy" in both education and health.

Similarly, the Copenhagen Consensus notes that "in countries where many people are infected, the benefits of deworming can be up to 60 times higher than the costs."


Mass treatment of all children in at-risk areas avoids the need to screen individuals for infection, leading to dramatic cost savings, and drugs are safe even for uninfected children. The school-based approach builds upon the documented importance of convenience in preventative healthcare, by bringing treatment to where children already are. 


The Deworm the World Initiative

The Deworm the World Initiative


The Deworm the World Initiative envisions a world where all at-risk children have improved health, increased access to education, and better livelihoods potential as a result of being free of intestinal worms. We work in close partnership with governments to enable elimination of intestinal worms as a public health problem.

  • We advocate for school-based deworming to policymakers, gaining and maintaining critical support amongst stakeholders responsible for children’s health and education.

  • We provide technical assistance to governments to launch, strengthen, and sustain high quality school-based deworming programs that leverage existing education and health infrastructure.

  • We employ an evidence-based approach to rigorously evaluate and learn from programs we support, iterating on program design alongside governments to maximize reach in a cost-effective manner


View our most recent results here


Deworm the World Initiative: Partnership Model


We advocate with governments to launch deworming programs, and work collaboratively with ministries of health and education to establish effective policies and governance structures. We support alignment of school-based deworming with other health and education priorities to enable long-term political and resource commitments, and share global best practices to improve cost-effectiveness and results.



We work with governments to develop locally appropriate campaigns that educate children and communities about the negative effects of worms, the importance of being dewormed, and behaviors to prevent infection. These campaigns increase acceptance and participation in deworming.

7.Monitoring and Evaluation

We help governments design monitoring and data management systems to ensure accurate treatment data and measure program performance. We conduct rigorous independent monitoring to evaluate the efficiency of key processes and validate program results; we share monitoring results with government implementers, using data to inform programmatic decision making.


Guided by World Health Organization protocols, we work with epidemiologists and local partners to assess worm prevalence and intensity through field surveys. We use the survey results to support the development and implementation of appropriate treatment strategies. Once deworming programs are in place, we support governments to assess the impact of sustained mass treatment on worm infection.

5.Training and Distribution Cascade

We support governments to design and coordinate an efficient multi-tier training and distribution cascade that is tailored to the local context, ensuring that knowledge and program materials are relayed from the national or state level all the way to the teachers responsible for administering deworming drugs.


We work closely with government partners to design their deworming program, develop operational plans and budgets, coordinate logistics, and provide on-the-ground support to ensure a high quality outcome.





6.Drug Management and Coordination 

We help governments evaluate appropriate treatment strategies, support drug procurement including through global pharmaceutical donation programs, and facilitate the development of robust protocols for tracking drug inventories and responding to adverse events.

Watch the video below to learn more about our work:

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Our Impact

Our Impact


Our Results At A Glance 


  • In 2017, the Deworm the World Initiative supported governments to treat more than 280 million children in India, Kenya, Ethiopia, Vietnam, and Nigeria.

  • We support India’s National Deworming Day, which targets all children ages 1-19 at schools and preschools; in 2017 the program treated more than 260 million children.

  • With our technical assistance, Kenya's National School-Based Deworming Program has consistently treated over 6 million children per year since 2012, dramatically reducing STH and schistosomiasis infection.

  • Since 2014, GiveWell has named the Deworm the World Initiative one of its top-rated charities.



In November 2018, GiveWell named the Deworm the World Initiative at Evidence Action one of its top-rated charities for the fifth year in a row, recommending us for its "excellent cost-effectiveness" and stating that “of the deworming charities we have evaluated, [Deworm the World] has the strongest track record of demonstrating that its programs are effective.”


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What's Next

The Deworm the World Initiative has ambitious plans to help eliminate the public health problem of parasitic worms in the coming years. Alongside evolving our technical assistance to existing government partners to  meet their needs, we are leveraging opportunities to accelerate treatment coverage for at-risk children, with a focus on high-need countries like Pakistan and Nigeria.

 We will:

  • Decrease the worm burden by expanding high-quality school-based deworming into new geographies

  • Build sustained government capacity to operate consistent, cost-effective, and high-quality school-based deworming programs

  • With partners, drive further progress towards achievement of the WHO target of STH treatment for 75% of at-risk children by 2020

National Deworming Day 2016

The Evidence for Deworming

The Evidence for Deworming

The evidence for mass school-based deworming

Parasitic worms are debilitating, widespread, and under-treated. School-based deworming is safe, cost-effective and scaleable. There is a robust evidence base for the work of the Deworm the World Initiative undertakes.

Deworming has important impacts on school participation, cognition and nutrition, and future earnings. Multiple rigorous studies have shown strong evidence of the effects of deworming, providing confidence in the benefits of treatment.  We summarize the evidence base for mass school-based deworming in this post.

School Participation

Parasitic worms limit educational outcomes for children. Not only are infected children less likely to be enrolled in school, but they are also less likely to attend school and more likely to perform lower on testing.

  • A long-term follow-up study linking aggregate infection data with individual socioeconomic data from the southern US in the 1910s found that a non-infected child was 20 percentage points more likely to be enrolled in school than an infected child, and was also 13 percentage points more likely to be literate.

  • Miguel and Kremer’s experimental evaluation in Western Kenya found that deworming treatment resulted in a 25% increase in attendance  at treatment schools.

  • In a long-term follow-up study in Kenya, evidence shows that among females, deworming increased the rate of passing the national primary school exit exam by 9.5 percentage points on a base of 41%.

Nutrition and Cognition

Children with parasitic worms suffer from nutritional impairment, impacting their growth and physical development. Deworming treatment leads to significant weight gains and allows more energy to be focused on growth and development.

  • A meta-analysis authored by Croke et al. (2016) finds a substantial and highly robust positive effect on child weight resulting from deworming. The effects are particularly large in areas with at least 20% prevalence; this is the same threshold at which the WHO currently recommends mass treatment.
  • A randomized controlled trial in Uganda finds that the provision of periodic anthelmintic treatment as a part of child health services resulted in an increase in weight gain of about 10% above expected weight gain when treatments were given twice a year, and an increase of 5% when the treatment was given annually.
  • Deworming has positive externalities even for children who are not directly treated. Owen Ozier’s 2016 study finds that younger siblings of children who were treated show cognitive gains comparable to between 0.5 and 0.8 years of schooling ten years later.

Future Earnings

Children who were dewormed have higher earnings in adulthood. Higher earnings contribute to improved economies and significant returns on investment for governments, especially considering the extremely low cost of treatment.


  • Hookworm infections could have explained as much as 22% of the income gap between the U.S. North and South in the early 1900s.
  • In Kenya, men who were treated as children worked 3.4 more hours per week, spent more time in entrepreneurial activities, and were more likely to work in higher-wage manufacturing jobs compared to their untreated peers. This long-term impact study in Kenya calculates a rate of return between 32-52% for governments who invest in deworming. 

  • Is mass treatment justified? On cost-effectiveness grounds we believe that it clearly is, as the cost of screening is four to ten times that of the treatment itself. Everyone agrees that children infected with worms should be treated. Because the drugs are very effective in treating worms, and are safe even for the uninfected, the WHO recommends mass drug administration as the clinical standard of care in areas where more than 20% of children are infected.
  • Deworming through schools, and preschools in some areas, provides the greatest opportunity to reach a high proportion of the at-risk population while minimizing costs through the use of existing infrastructure.

Why Mass Treatment


Where We Work

Where We Work

Where we work


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  • India is the country with the highest number of worm infections globally; 220 million children at risk for STH infections.

  • We provide technical assistance to the Ministry of Health and Family Welfare along with customized assistance to eleven states: Bihar, Chattisgarh, Haryana, Jharkhand, Madhya Pradesh, Rajasthan, Telangana, Tripura, Uttarakhand, Uttar Pradesh, and Karnataka.

  • In February 2015, we helped the national government initiate National Deworming Day (NDD). The program reach extends to preschools, government schools, private schools, and out-of-school children, targeting all children aged 1-19. As of February 2018, NDD scaled up to 34 states and union territories, with the government reporting treatment of over 266 million children.


  • In Kenya, more than 5 million school-age children are at risk of intestinal parasitic worms, including STH and schistosomes.

  • We have supported the Government of Kenya’s school-based deworming at national scale since 2012, annually treating children at risk for STH and schistosomiasis through a collaboration between the Ministry of Education and Ministry of Health. In 2017, the program treated 5.9 million children (including 519,232 for schistosomiasis) across 27 counties. The program reached 80% of at-risk children, exceeding the WHO’s 75% coverage target.

  • Across the 27 counties, STH infections have steadily reduced, from baseline infection of 33.4% to 15.9% after three years of treatment (including a 19% reduction in moderate-to-heavy intensity infections); schistosomiasis infection reductions have also been achieved.


  • Ethiopia is the fifth most burdened country globally by childhood worm infection; 18.4 million school-age children and 6.6 million preschool-age children are at risk for STH infection. Approximately, 14.6 million school-age children are at risk of schistosomiasis.

  • The national deworming program is led by the Federal Ministry of Health, and implemented in partnership with the Ministry of Education and the Ethiopian Public Health Institute. We partner with the Schistosomiasis Control Initiative (SCI) to provide technical assistance to national and sub-national government ministries.

  • As of 2017, the Government of Ethiopia has treated roughly 15 million school-age children children for STH and 4.6 million for schistosomiasis. The program intends to distribute over 100 million deworming treatments to school-age children by 2019.


  • Nigeria is the third most burdened country in terms of its number of children at risk for worm infections. Approximately 28.6 million school-age children are at risk for STH infection; 23.8 school-age children are at risk of schistosomiasis.

  • We partner with Cross River state and RTI International to provide technical assistance to the State Ministries of Health and Education; our support for school-based treatment complements community-based treatment of other neglected tropical diseases. In its first year of operation, the program treated over 492,179 school-age children for STH and schistosomiasis.

  • We are engaging with the Federal Ministry of Health to support development of a national-level deworming strategy and collaborating on further expansion of school-based deworming in Nigeria. In 2017, our state level support expanded to three additional partner states - Rivers, Oyo, and Ogun - and treated 3.5 million children.


  • In Vietnam, we partner with Thrive Networks to provide technical assistance to the Government of Vietnam’s deworming program in four provinces.

  • In November 2017 the program treated over 740,000 children, achieving over 90% coverage.

  • Exciting research opportunities exist as part of this program. We are conducting a randomized controlled trial (RCT) to understand whether a school-based hygiene education package is successful and cost-effective at reducing reinfection among school-age children when combined with school-based deworming.


  • In 2016 we worked with our partner, Interactive Research & Development (IRD), in coordination with provincial governments in Pakistan, to carry out the country’s first national-level STH survey to map worm prevalence and intensity.

  • Data collected from the survey revealed an estimated 17 million school-age children require annual treatment for STH.

  • We plan to work with health and education stakeholders at the national and provincial level to support the initiation of a school-based deworming program in late 2018 in areas recommended for mass treatment, continuing our partnership with IRD.


Learn More

Learn More

Learn more about the Deworm the World Initiative in the blog posts below.

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