Parasitic Worms

Electron micrograph of an adult male Schistosoma worm. The bar (bottom left) represents a magnification of 500 μm. (David Williams /

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Notice about research

Giving What We Can no longer conducts its own research into charities and cause areas. Instead, we're relying on the work of organizations including J-PAL, GiveWell, and the Open Philanthropy Project, which are in a better position to provide more comprehensive research coverage.

These research reports represent our thinking as of late 2016, and much of the information will be relevant for making decisions about how to donate as effectively as possible. However we are not updating them and the information may therefore be out of date.

Impact Summary

  • Importance: 2/5
  • Tractability: 5/5
  • Neglectedness: 4/5
Learn More

Charity Impact

  • Cost Effectiveness: 4.5/5
  • Robustness of Evidence: 2.5/5
  • Track Record: 3.5/5
  • Room for More Funding: Yes
Learn More Deworm The World Initiative

Charity Impact

  • Cost Effectiveness: 4.5/5
  • Robustness of Evidence: 3/5
  • Track Record: 4/5
  • Room for More Funding: Yes
Learn More Schistosomiasis Control Initiative

Fast Facts

  • The CDC estimates that 700 million people are at risk of schistosomiasis in 74 countries, with 240 million already affected.
  • The disease ranks second only to malaria as the most common parasitic disease.
  • Praziquantel, an inexpensive anti-parasitic drug has been demonstrated to be highly effective in treating schistosomiasis. The Schistosomiasis Control Initiative (SCI), one of our top charities, works to deliver this drug in the world's neediest contexts.

Donating to an organisation which focuses on treating children with parasitic worms through mass drug administration (MDA) represents an excellent giving opportunity for a donor focused on having a high impact on both health and economic empowerment. As the drugs used to treat parasitic worms have only mild side effects, they can be administered without the need for individual diagnosis (which is both expensive and requires medical expertise). In addition, the drugs used to treat parasitic worms are cheap to manufacture and often donated by pharmaceutical corporations. This means that children can be dewormed effectively at very low cost.

We focus here on MDA of praziquantel (used to treat schistosomiasis) and albendazole (used to treat soil-transmitted helminth infections) as these treat two diseases both with very high prevalence, and strong evidence of treatment efficacy. There is some limited evidence that suggests that children in high prevalence areas who are dewormed with these drugs have substantially higher lifetime incomes. There is also limited evidence that they may also complete more years of schooling, and have higher levels of general health. The evidence supporting the efficacy of deworming is complicated by the many different types of infection, and long timescales involved. Although there is still disagreement over the precise extent of the flow-through effects of deworming, the extremely low cost of treatment still implies that it can be expected to be a highly effective intervention - impacts on long-term productivity and wider health benefits simply add further to the case for MDA as an effective intervention.