The UW School of Public Health is turning research into action to interrupt the transmission of parasitic worms in developing countries.

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For two billion people around the planet, anemia, weakness and malaise are part of daily life.

These symptoms are part of living with soil-transmitted helminths – more commonly known as intestinal worms – that inhabit victims’ bellies, sapping their nutrients and stunting their physical and cognitive development.

In countries where the disease is prevalent, soil-transmitted helminths have long been a public health problem and a human rights issue — and the UW School of Public Health is doing something about it. Researchers are playing a leading role in DeWorm3, a project based at the Natural History Museum in London and funded by the Bill & Melinda Gates Foundation.

DeWorm3 is providing the platform for one of the largest implementation science projects in the field to date. Its core mission? To interrupt the transmission of intestinal worms.

Intestinal worms are all over the world, but in countries like Japan and the United States, public health officials have been able to control or even stop transmission of the disease. But  impoverished areas of Africa and Asia are still battling the cycle. Why haven’t we been able to eradicate this problem on a global scale yet?

The key culprits are limited access to clean water and sanitation resources – as well as the fact that only preschool- and school-age children receive treatment in current deworming programs, says Arianna Means, ’17, graduate of the world’s first Ph.D. program in metrics and implementation science and a DeWorm3 research scientist.

Worm infections come from eating unwashed fruit and vegetables that have traces of fecal matter, from drinking contaminated water or simply from walking barefoot: Some worms migrate through the skin.

Arianna Means, graduate of the world’s first Ph.D. program in metrics and implementation science and a DeWorm3 research scientist. (University of Washington)
Arianna Means, graduate of the world’s first Ph.D. program in metrics and implementation science and a DeWorm3 research scientist. (University of Washington)

Because only children are being treated, they might be rid of an infection one day, then go back to their earthen-floor homes and get reinfected the next. “Unless you can get really intense community-wide treatment going, disrupting the transmission is pretty challenging,” says Means.

Therein lies the solution: programs that treat everyone, in all households, more than once a year.

Mass drug administration programs have targeted entire communities before, so we know the strategy works. A large-scale effort to squash another parasitic disease, lymphatic filariasis (commonly known as elephantiasis), kicked off in 2000. Community-wide treatment helped transmission rates drop 43 percent in just 15 years. More than 800 million people have been treated so far, and in some countries, the transmission cycle has been interrupted. The hope is for complete elimination of the disease by 2020.

There’s an opportunity here, says Means, to leverage treatment platforms already in place in Benin, Malawi and India for DeWorm3’s efforts. In fact, lymphatic filariasis and intestinal worm treatments share a drug treatment: albendazole.

This is what implementation science is all about.

The current U.S. estimate for going from the discovery of an intervention to its implementation at scale is 17 years, says Kenny Sherr, associate professor of global health at the UW. “This is what we refer to as the ‘know-do’ gap,” he explains. “What implementation science tries to do is close this gap – to take what we know works in terms of health interventions from trials and improve the speed and quality of its implementation at scale.”

Kenny Sherr, associate professor of global health at the UW. (University of Washington)
Kenny Sherr, associate professor of global health at the UW. (University of Washington)

Starting this year, at the end of the lymphatic filariasis programs in those three countries, DeWorm3 will randomly assign communities to either maintain the standard program of only treating preschool- and school-age children for intestinal worms – or switch to a highly intensive treatment plan where everyone in the community is treated twice per year. Along the way, DeWorm3 will conduct further implementation science research to understand best practices in intervention delivery and opportunities to maximize community participation.

In 2020, both types of communities will stop all treatment. Two years later, DeWorm3 will compare the groups and determine whether the intensified treatment program was more successful. If so, the team will work with policymakers to develop relevant guidelines that could be used to bring the intensified intervention to scale.

The potential impact of DeWorm3’s work for an infection-free world is unparalleled, says Means. “For a parent, just knowing your kid isn’t at risk of contracting an infection is huge,” she says. “There’s peace of mind in knowing your child can run around barefoot without getting a belly full of worms.”

Learn more about the University of Washington School of Public Health.