Guinea worm: A nasty parasite is nearly eradicated, but the push for zero cases will require patience
Published in Health & Fitness
A painful, parasitic disease that once infected 3.5 million people per year is tantalizingly close to being eradicated.
On Jan. 24, 2023, The Carter Center, a nonprofit founded by former U.S. President Jimmy Carter, announced that “Guinea worm is poised to become the second human disease in history to be eradicated,” having recorded just 12 cases worldwide in 2022. It represents the lowest annual figure since 1986, when the Carter Center began leading global efforts to eradicate Guinea worm disease.
I have been working as a parasitologist for over two decades. I know the suffering that parasitic diseases like Guinea worm infections inflict on humanity, especially on the world’s most vulnerable and poor communities. My own research on African sleeping sickness – a deadly disease caused by a parasite carried by tsetse flies – has shown me how difficult it is to fight these diseases.
Thanks to a massive global effort, Guinea worm is now almost gone. However, humanity has been tantalizingly close to fully eradicating Guinea worm for many years. To take the final step from almost gone to fully eradicated is not easy, but with patience and vigilance, it is possible.
Guinea worms are parasitic nematodes that infect humans and a few other animals. They live in ponds, rivers and creeks all across Africa but are mostly endemic to sub-Saharan Africa.
A Guinea worm infection is a nasty experience. The worm mainly infects people after they drink water that is contaminated with tiny crustaceans called copepods that are infected with worm larvae. Most people don’t realize they are infected for about a year – roughly the time it takes for the larvae to burrow their way out of the stomach and into the abdominal cavity, develop into adults and mate. Once the females mature into pregnant worms, the horror show begins.
The pregnant worms must get back to the water to give birth, so they crawl down to the lower leg or foot. Once there, they burrow out through an incredibly painful blister in a process that can take weeks. The intense pain causes people to plunge their leg into water to get relief, and this is when the worm expels her larvae, starting the cycle anew.
There are no vaccines or drugs for Guinea worm. The current best treatment is very low-tech: treat the wound and slowly extract the worm over several painful weeks. Due to the intense pain, infected adults cannot work or provide for their families. Infected kids miss school and fall behind on their education. Though there are usually no long-term complications, infection confers no immunity, so people can get infected repeatedly over their lifetimes, too.
Guinea worm is awful, so I welcome any news of removing it from the list of diseases that affect people. But alongside hope, a healthy dose of realism is needed: Eradicating any disease is difficult. So far, humanity has succeeded only with smallpox, which was eradicated with the help of vaccines in the late 1970s after 200 years of effort.
A disease like Guinea worm is a distinctly different challenge. Eradication will not come from a medical solution like a pill or vaccine. Instead, people will have to change their behavior. The ideas are simple, but that does not mean this will be easy.