Dracunculiasis is also known as guinea-worm disease. It is a crippling parasitic disease caused by Dracunculus medinensis, a long, thread-like worm. It is transmitted exclusively when people drink stagnant water contaminated with parasite-infected water fleas. The acidic environment of the stomach and duodenum kills the copepods. The larvae are subsequently released in the stomach or small intestine and penetrate the mucosa to mate and mature in the abdomen or retroperitoneal space approximately 60-90 days after initial infection. When the worm movement in body, usually to the lower leg, through the subcutaneous tissues, it leads to intense pain localized to its path of travel. The painful, burning sensation experienced by infected people has led to the disease being called "the fiery serpent". When the Guinea worm is ready to come out of the body, it creates a painful burning blister on the skin. When the infected person immerses the blister in cool water to ease the symptoms, the Guinea worm breaks through the blister and part of the worm is exposed. There is no specific drug to treat or prevent GWD. There is also no vaccine to prevent GWD.