This post has been updated.
Dracunculiasis—or, as it’s better known, Guinea worm disease—is the stuff of nightmares. A parasite spread through contaminated water, it is contracted when consuming water from a contaminated sources, which contains larvae of the worm. Male and female larvae mate, and about a year after a grown female worm creates a painful lesion in the skin of the host (generally on a foot or leg) and slowly emerges. As the pain can be crippling, the patient seeks water to relieve the burning sensation, which stimulates the worm to release its own larvae in the water, which then gets drunk—and so on, and so forth.
There are no medications or vaccines for the Guinea worm disease, and the remedy consists in treating contaminated bodies of water and, on the patient’s hand, pulling out the worm from the body, a few centimeter at a time, which can cause weeks of disability, since it can grow up to three feet of length. People don’t develop immunity to the disease, and can be affected more than once in contaminated areas.
In 1986, 3.5 million people were affected by it every year. Currently, thanks to a campaign lead for the past 30 years by the Carter Center, there are only 18 cases recorded, Don Bundy—a senior advisor for neglected tropical diseases in Africa—told Quartz. The parasite is on its way to complete eradication, which is on track to be certified in 2016.
This is an optimal trajectory to observe in the spread of a disease, and one that was achieved through a rather simple, if demanding, strategy: combining the treatment of water bodies hosting the parasites with education, teaching local population to filter their drinking water. Part of what made the success possible, Bundy said, is that the campaigns could use the system put in place for the eradication of polio.
The Guinea worm disease is one of ten ”neglected tropical diseases,” or potentially debilitating, but treatable conditions that only persist amongst the world’s poorest communities, affecting an estimated 1.5 billion people around the world, primarily in Africa and India, where the eradication of such diseases would bring great economic advantages to the affected communities.
Unlike the Guinea worm, for which there is no drug available, for most of these diseases the key to eradication is access to medicine. In 2012, 14 pharmaceutical companies pledged to donate drugs worth over $17 billion to treat these diseases by 2020 (river blindness and sleeping sickness should be next in line), but some of them were developed for the veterinary market, which is much more lucrative than the poor section of human population that needs them, and could use some improvement for human treatment.
Update: Since Quartz spoke to Donald Bundy on Dec. 12, 3 more cases of Guinea worm disease have been detected, bringing the total up to 21.