worm involves submerging the affected body part in water to help coax the worm out. The site is then cleaned thoroughly. Then, slight pressure is applied to the worm as it is slowly pulled out of the wound. To avoid breaking the worm, pulling should stop when resistance is met. Full extraction of the female guinea worm usually takes several days. After each day's worth of extraction, the exposed portion of the worm is wrapped around a piece of rolled-up gauze or small stick to maintain tension. This method of wrapping the worm around a stick or gauze is speculated to be the source for the Rod of Asclepius, the symbol of medicine. Once secure, topical antibiotics are applied to the affected region, to help prevent secondary infections due to bacteria, which is then wrapped in gauze to protect the wound. The same steps are repeated each day until the whole worm has been removed from the lesion. Eradication program In the 1980s, the Carter Center initiated a program to eradicate the guinea worm. The campaign began in 1980 at the US Centers for Disease Control and Prevention. In 1984, the CDC was appointed as the World Health Organization Collaborating Center for research, training, and eradication of D. medinensis. More than twenty countries were affected by guinea worms in 1986. That year, WHO started the eradication program with the Carter Center leading the effort. The program included education of people in affected areas that the disease was caused by larvae in drinking water, isolation and support for affected people, and – crucially – widespread distribution of net filters and pipe filters for drinking water, and education about the importance of using them. , the species has been reported to be near eradication. The International Commission for the Certification of Dracunculus Eradication has certified 198 countries, territories, and other WHO represented areas. In January 2015, eight countries remained to be certified as D. medinensis free. These eight countries are Angola, the Democratic Republic of the Congo, Kenya, Sudan, Chad, Ethiopia, Mali, and South Sudan. Of these, Chad, Ethiopia, Mali, and South Sudan are the only remaining endemic countries. See also Planned extinction Explanatory notes References External links How to Slay a Dragon – documentary by Clifford Bestall, broadcast on Al Jazeera English, Spring 2014 (video, 47 min.) Nematodes described in 1758 Parasitic nematodes of humans Spirurida Taxa named by Carl Linnaeus