The wound remains intensely painful as the worm slowly emerges over several weeks to months.In an attempt to alleviate the excruciating burning pain, the host will nearly always attempt to submerge the affected body part in water. When this occurs and the worm is exposed to water, it spews a white substance into the water containing thousands of larvae. As the worm emerges, the open blister often becomes infected with bacteria, resulting in redness and swelling, the formation of abscesses, or in severe cases gangrene, sepsis or lockjaw. When the secondary infection is near a joint (typically the ankle), the damage to the joint can result in stiffness, arthritis, or contractures.Infected people commonly harbor multiple worms – with an average 1.8 worms per person; up to 40 at a time – which will emerge from separate blisters at the same time. 90% of worms emerge from the legs or feet. However, worms can emerge from anywhere on the body. Cause
Dracunculiasis is caused by infection with the roundworm Dracunculus medinensis. D. medinensis larvae reside within small aquatic crustaceans called copepods or water fleas. When humans drink the water, they can unintentionally ingest infected copepods. During digestion the copepods die, releasing the D. medinensis larvae. The larvae exit the digestive tract by penetrating the stomach and intestine, taking refuge in the abdomen or retroperitoneal space. Over the next two to three months the larvae develop into adult male and female worms.
Around 1% of dracunculiasis cases result in death from secondary infections of the wound.When dracunculiasis was widespread, it would often affect entire villages at once. Outbreaks occurring during planting and harvesting seasons severely impair a communitys agricultural operations – earning dracunculiasis the moniker "empty granary disease" in some places. Communities affected by dracunculiasis also see reduced school attendance as children of affected parents must take over farm or household duties, and affected children may be physically prevented from walking to school for weeks.Infection does not create immunity, so people can repeatedly experience dracunculiasis throughout their lives. Prevention
There is no vaccine for dracunculiasis, and once infected with D. medinensis there is no way to prevent the disease from running its full course. Consequently, nearly all effort to reduce the burden of dracunculiasis focuses on preventing the transmission of D. medinensis from person to person. This is primarily accomplished by filtering drinking water to physically remove copepods. Nylon filters, finely woven cloth, or specialized filter straws are all effective means of copepod removal. Sources of drinking water can be treated with the larvicide temephos, which kills copepods. Where possible, open sources of drinking water are replaced by deep wells that can serve as new sources of clean water. Public education campaigns inform people in affected areas how dracunculiasis spreads and encourage those with the disease to avoid soaking their wounds in bodies of water that are used for drinking. Epidemiology
Dracunculiasis is nearly eradicated, with just 15 cases reported worldwide in 2021.