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National Deworming Day 2016
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The Problem: Parasitic Worms


The Problem: Parasitic Worms

There are more than 870 million children at risk of parasitic worm infections worldwide. A significant body of evidence shows that worm infections negatively impact children’s health, well-being, education, and long-term economic future.

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 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. 

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


Treatment with a simple pill is universally recognized as a safe and simple solution. Evidence Action's Deworm the World Initiative focuses on treatment delivered through existing school infrastructure.  This is highly cost-effective and accepted well by communities, and able to reach hundreds of millions of children.

Rigorous evidence shows that school-based deworming programs can improve health and education outcomes for children at a cost of less than $0.50 per year.

In November 2016, GiveWell named the Deworm the World Initiative at Evidence Action one of its top-rated charities for a fourth year in a row, stating that it is recommended as "a program with a strong track record and excellent cost-effectiveness."


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 recommends treating children when they are in school, citing research that notes that "in countries where many people are infected, the benefits of deworming can be up to 60 times higher than the costs."


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 with governments around the world to eliminate the public health threat of worms through scaling up school-based mass deworming programs. 
  • We advocate for national school-based deworming to policymakers, and provide technical assistance to governments to launch, strengthen, and sustain school-based deworming programs. 
  • We focus on large-scale school-based deworming programs as they leverage existing infrastructure that result in treatment coverage of over 80% of at-risk children.


We advocate with governments to launch deworming programs, then work collaboratively with them to establish effective policies and long-term commitment by building their capacity, mobilizing domestic support and sharing global best practices to improve cost-effectiveness and results.


We work with governments and communications experts to design locally appropriate awareness campaigns to communicate messages through a wide variety of channels to increase public acceptance and effectiveness of deworming programs. 


We help governments evaluate appropriate drug treatment strategies and dosage, support drug procurement including through global pharmaceutical donation programs, and design robust serious adverse event protocols and drug tracking systems.


We work with epidemiologists and local partners to assess worm prevalence and intensity, obtaining data to develop a targeted treatment strategy and to determine the impact of programs once they are in place.



We help governments design monitoring systems to measure effectiveness in achieving intended program objectives. We also conduct independent monitoring to validate program results, and evaluate the impact of programs in reducing worm prevalence and intensity.


We work closely with ministries of education and health to design a program with joint ownership, develop operational plans and budgets, coordinate logistics, and provide on-the-ground support to ensure a high quality outcome.



We consistently design and support training through an efficient multi-tier cascade approach that is tailored to the local context, ensuring knowledge reaches from the national level all the way to the teachers responsible for administering deworming medication.

National Deworming Day 2016

The Evidence for Deworming

The Evidence for Deworming


School Participation

Parasitic worms are debilitating, widespread, and under-treated. School-based deworming is safe, cost-effective and scale-able. What is the evidence base for the work that  the Deworm the World Initiative undertakes? 

We summarize the evidence base for mass school-based deworming programs in this post. Here are key findings across the key impacts of deworming: school participation, future earnings, and cognition and nutrition.

Future Earnings

  • Hookworm infections could have explained as much as 22% of the income gap between the U.S. North and South.
  • 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. This long-term impact study in Kenya calculates a rate of return for governments who invest in deworming of 32-52%.

Nutrition and Cognition

  • “Does Mass Deworming Affect Child Nutrition?: Meta-analysis, Cost-Effectiveness, and Statistical Power” authored by Kevin Croke, Joan Hamory Hicks, Eric Hsu, Michael Kremer, and Edward Miguel, finds a “substantial” and “highly robust” positive effect on child weight resulting from deworming. The effects are particularly large in areas above 20% prevalence; this is the same threshold at which the WHO currently recommends mass treatment. The authors also note the cost-effectiveness of deworming, with "the estimated average weight gain per dollar expenditure from deworming...more than 35 times that from school feeding programs as estimated in RCTs."

  • A randomized health intervention that provided iron, Vitamin A and deworming drugs to Indian preschool children in poor areas of Delhi found a significant gain in child weight and school participation compared to intervention with Vitamin A alone. Absenteeism was reduced by one-fifth in the treatment group. We do note, however, that the large DEVTA trial found no impacts of deworming or Vitamin A supplementation on mortality in a rural area where worm loads were light. We prioritize, and urge our government partners to prioritize, investment in areas where worm loads are high. 

  • A randomized controlled trial in Uganda (Alderman and colleagues, 2006) 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.

  • Chronic infections in childhood (from diarrhea, to malaria, to worms) generate inflammatory (immune defense) responses lead substantial energy to be diverted from growth. There are interaction effects too, with deworming, for example, making it easier to fight off malaria. More generally, in their summary of deworming, the WHO points to several channels by which worms may impair nutrition, and notes several studies that can support these claims.

  • Owen Ozier’s study on the long-term effects of early childhood deworming suggests that reduced exposure to worm infections may improve cognition for children less than one year of age. These young children in the catchment area of treatment schools showed large gains on cognitive tests about ten years later.

  • Is mass treatment justified? On cost-effectiveness grounds we believe that it clearly is, as the cost of treatment is cheaper than individual screening. The WHO states that the cost of screening is four to ten times that of the treatment itself. Because the drugs are very safe and has no side effects for the uninfected, the WHO does not recommend individual screening. The WHO instead recommends mass drug administration 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 government infrastructure.

Why Mass Treatment


Our Impact

Our Impact

Our Results At A Glance 


What's Next? 

Evidence Action’s Deworm the World Initiative has ambitious plans in the next several years to eliminate the public health threat of parasitic worms. We are poised to take advantage of an unparalleled window of opportunity to rapidly accelerate treatment coverage of children worldwide.

Multilateral organizations, pharmaceutical companies, NGOs, and governments are prioritizing the elimination of neglected tropical diseases, allocating resources and developing roadmaps for scaling up treatment. 

We will: 

  • Decrease the worm burden by expanding school-based deworming into new geographies. 
  • Build sustained government capacity to operate consistent, cost-effective, and high-quality school-based deworming programs. 
  • Catalyze partners to adopt school-based deworming models and associated best practices to close the treatment gap.

Where We Work

Where We Work


We are helping put deworming and a world free of worms on the global agenda.

Accelerating treatment to cover the at-risk school-age children in the highest-burden countries is the most cost-effective and efficient way to achieve the WHO goal of 75% coverage of school-age children. 

This is where we focus. 

The Deworm the World Initiative scales school-based deworming in these high-need geographies. 

We have expanded our  technical assistance support to a national school-based deworming program in India and Ethiopia, and started work in Nigeria and Vietnam, while maintaining technical support in Kenya and states in India were we have previously worked. 


Where we Work


  • Our India team provides technical assistance to eight states: Bihar, Rajasthan, Madhya Pradesh, Uttar Pradesh, Jharkhand, Chhattisgarh, Telangana, and Tripura.
  • In February 2015, we helped the national government initiate the now-twice-annual National Deworming Day (NDD). The government reported treatment of 140 million children in the first round of the program. 
  • In 2016, NDD was expanded to all 36 states and union territories in India, targeting 220 million children for school-based and anganwadi-based (preschool) treatment for STH. The Government of India reports that the program has treated 179 million children in February 2016. 
  • In August 2016, a second round of treatment took place in states where high prevalence indicates a need for twice-annual treatment. 


  • Thrive Networks is our partner in Vietnam. The program there supports deworming in four provinces. The program has achieved over 90% coverage in its first round of treatment this year with another round underway at the end of 2016. We are also planning an RCT to evaluate the effects of a hygiene intervention on worm infections in 2017.  


  • We’re entering our fifth year at national scale in Kenya. The Government of Kenya’s National School Based Deworming Program routinely treats ~ 6 million children for both STH and schistosomiasis. Year 3 results were released during the first week of March 2016 in this booklet. 6.1 million children were treated. Year 4 results will be released in early 2017. 


  • In Ethiopia, we partner with the Schistosomiasis Control Initiative (SCI) in supporting the Federal Ministry of Health’s national school-based deworming program. The program is projected to distribute over 100 million deworming treatments to school-age children over the next five years.


  • Nigeria is second to India in its number of children at risk for intestinal worm infections. In 2015, we conducted an opportunity analysis and exploratory visits to four state governments in Nigeria, with the aim of determining which could be a good starting point for our support there.
  • In early 2016, we started providing technical assistance for school-based deworming in Cross River state with a partner organization (RTI) that supports community-based treatment for other endemic NTDs in the state. We are now pursuing expansion into three additional states to scale up treatment of STH and schistosomiasis.