Only 10 cases of guinea worm were reported in 2025, down from an estimated 3.5 million cases per year when the elimination campaign began four decades ago. The disease is an ancient one, believed by some to be the “fiery serpents” that beset the ancient Israelites in The Book of Numbers. It is treated by carefully wrapping the parasite around a small stick as it painfully emerges over the course of weeks. This may be the inspiration for the Staff of Asclepius (⚕), the predominant symbol of medicine showing a a serpent wrapped around a rod.
When I was studying mathematical modelling of infectious diseases at the University of Ottawa in the mid 2010s, the question was whether Jimmy Carter would outlive the guinea worm. Tragically, he did not, but his life’s work helped to prevent an estimated 100 million cases of the disabling disease and made him a hero in global health.
While we are within spitting distance of zero cases in humans, true eradication will be more difficult due to significant animal reservoirs of the disease. The press release notes nearly 700 reported cases in animals across six countries (and who knows how many unreported cases). These non-human reservoirs pose a significant barrier to true eradication, since the disease must die out not only in human populations but also in wildlife.
So far, only two infectious diseases have been eliminated, smallpox in humans and rinderpest in cattle, water buffalo, and other even-toed ungulates. Smallpox had no non-human reservoirs, making it an ideal target for eradication. Rinderpest’s persistence in wildlife posed an important but not insurmountable challenge to its eventual eradication in 2011. This recent news of all-time low counts for guinea worm infection put us one step closer to closing the book forever on a second human infectious disease.
Hat tip to bookofjoe on HackerNews.