It all starts with a drink of water contaminated with the worm’s larvae. In a human host, the larvae penetrate the digestive tract and enter the body cavity to grow quietly. Within a few months, the male and female worms meet and mate. Then the males die. The surviving female worms mature, reach 60 to 100 centimeters (2 to 3 feet), and migrate to the victim’s muscles. About 10 to 14 months after that tainted drink, the female worms burn through the skin by leaching acid, creating a scorching blister. This can happen anywhere in the body, but it’s usually in the legs or feet.
Not coincidentally, dipping the blister in water soothes the pain – and gives the female worm a chance to burst out of the wound and spew out a milky mush with millions of larvae, starting the cycle all over again. From there, the victim can slowly try to pull the worm out. But pulling too fast can break the thin parasite (only 1 to 2 mm wide), causing an infection. Instead, it should be removed slowly, usually by winding the end around a piece of gauze or twig and turning it a few times a day. The process often takes weeks.
The nasty culprit here is the guinea worm (Dracunculus medinensis). The infection is called dracunculiasis, Latin for “stricken by little dragons,” after the burning blisters they create on their way out.
In 1986, there were an estimated 3.5 million cases of dracunculiasis in 21 countries on two continents. But today we’re on the cusp of completely eradicating the fiery infection, thanks in large part to the work of the Carter Center, a philanthropic organization co-founded by former President Jimmy Carter and in charge of the fight against Guinean worms. .
Last week, the fledgling country of South Sudan announced it had not had a case in 15 consecutive months — longer than the worm’s life cycle. And the World Health Organization has certified 199 countries, territories and territories as dracunculiasis-free. That means there were only 30 cases worldwide in 2017 – 15 in Chad and 15 in Ethiopia.
“The people and government of South Sudan have reached a major milestone in the global effort to eradicate helminth disease in Guinea,” Carter said in a statement. “South Sudan’s success shows that people can work together for the common good. We look forward to WHO’s certification in the coming years that South Sudan has won the battle against this ancient scourge. We are within reach of a world free of Guinea worm disease.”
The Carter Center and other groups have worked to eliminate the worm by distributing fabric water filters, advocating for safe drinking water sources, treating victims, applying insecticide to polluted ponds, educating communities about transmission and monitoring cases.
There were also complex environmental and political challenges to the eradication efforts. For example, during the civil war in Sudan, Carter personally negotiated a 1995 ceasefire agreement that would allow health workers to conduct their intervention efforts. South Sudan, which gained independence in 2011, prevailed despite long rainy seasons and high incidence rates.
Health advocates continue their work in Chad and Ethiopia, including detecting infections in dogs.
If they can wipe out the few remaining cases, dracunculiasis will be the second human disease to be eradicated worldwide. The first was smallpox, which was declared eradicated in 1980. Rinderpest, a deadly virus in cattle, was eradicated in 2011.
List image by CDC/Carter Center