The Unstoppable Makoy Samuel Yibi and the Quest to Eradicate Guinea Worm

Makoy Samuel Yibi

Makoy Samuel Yibi has dedicated his career to eradicating Guinea worm disease, one of the most painful and debilitating diseases in the world. As the head of South Sudan’s Guinea Worm Eradication Program, Makoy has helped reduce cases in his country from over 3 million to just 2 in 2023. His tireless efforts traversing rugged terrain and establishing community relationships have brought the world tantalizingly close to fully eradicating the disease.

The horrific Guinea worm parasite emerges from human hosts in a torturous process that can leave victims incapacitated for months, and often permanently disabled. This prevents people from working and growing food, creating devastating consequences for impoverished communities. Makoy witnessed this suffering firsthand early in his career, motivating his mission to eradicate the disease. He now leads an army of volunteers investigating rumors and containing outbreaks through patient isolation and controlled worm extraction.

Simultaneously, Makoy works to prevent future infections by distributing water filters and educating people on safe water practices. His robust health system has strengthened broader public health efforts like childhood vaccination. Makoy has also benefitted enormously from his partnership with former US President Jimmy Carter and the Carter Center’s unwavering global eradication campaign.

Makoy Samuel Yibi (left) with former President Jimmy Carter in South Sudan, 2010. (Photo: The Carter Center/ L. Gubb)

While the last few cases will prove challenging, as Guinea worm occasionally jumps between humans and animals, Makoy remains optimistic that eradication is imminent. He has seen afflicted communities “energized” and empowered through elimination. If the unstoppable Makoy has his way, the end of the Guinea worm parasite is within reach.

Read the post by Bill Gates on GatesNotes: Makoy Samuel Yibi won’t stop until the world eradicates its next disease

Read a tribute to President Jimmy Carter by Mr. Makoy: President Jimmy Carter, My Hero and Strength

Watch the video by Bill Gates: Bill Gates’s Heroes in the Field: Makoy Samuel Yibi

Guinea worm once infected 3.5 million people every year. Thanks to heroes like Makoy, that number dropped to 13 last year.


Bill Gates: In 2006, over 20,000 people in South Sudan had Guinea worm disease, about 90% of the world’s cases. But last year, there were only two cases – a fantastic turnaround, much due to Makoy Samuel Yibi, head of South Sudan’s Guinea worm eradication program.

Makoy Samuel Yibi: Guinea worm is a parasite that looks like spaghetti. People get infected when they drink water contaminated with worm larvae. The larvae mate and the female worm grows, emerging 10-14 months later. Imagine a 1 meter worm coming out of your body, sometimes 30-40 worms from one person – very nasty. There is fever, swelling, then a blister forms where the worm emerges. We put that body part in water so the worm releases larvae as we slowly pull it out.

Sometimes half a village gets Guinea worm disease, seriously disrupting livelihoods and causing hunger and poverty cycles. There is no cure or treatment, but we can eradicate it. The key strategy is surveillance – detecting cases, providing water filters to prevent contamination, and stopping infected people from passing it to others.

Communities are key stakeholders in everything we do. With Carter Center support, we mobilized communities nationwide. We have 5,000 village volunteers selected by the communities. This structure enabled building a health system from the bottom up.

We’re dealing with the last few Guinea worm cases now. The worm judges our work – each case means we must learn and do better. We won’t stop until the last case is eliminated in South Sudan.

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