Dracunculiasis Guinea Worm Disease

Dracunculiasis Commonly as the Guinea worm disease Causes by the largest of tissue parasites affecting humans, the parasitic round worm Dracunculus medinensis Transmitted to people when they drink water containing copepods that are infected with Dracunculus medinensis Rarely fatal but often incapacitating for several months Not currently possible to drugs prevent or treat with

Historical: Thought to be referred to in a book written in Egypt 3,500 years ago (the Ebers' Papyrus). Probably the "fiery serpent" referred to in the Bible. Also may be the coiled serpents on the "Caduceus" the symbol of a physician.

Dracunculus medinensis Epidemiology . In 1986, there were an estimated 3.5 million cases of Guinea worm in 20 endemic nations in Asia and Africa. The number of cases has been reduced by more than 99% to 3,190 in 2009, 3,185 of them in the four remaining endemic nations of Africa: Sudan, Ghana, Mali and Ethiopia.

Map-2002

The life cycle

Life Cycle Adult females in subcutaneous tissues of the legs and arms. Blister forms over nematode. Breaks when exposed to water. Nematode uterus ruptures and discharges first stage juveniles into the water (ovoviviparous). Juveniles ingested by copepod (intermediate host, 2 molts within copepod). Copepod swallowed by human. Juveniles migrate via lymph system. Develop to adults in subcutaneous tissues.

MORPHOLOGY

Morphology Dracunculus medinensis is usually white The adult female is among the longest nematodes Often measures one meter in length No more than 1-2 mm wide (thin like spaghetti) The male is generally much smaller and raerly recovered from humans because he dies shortly afer mating

Symptoms

Symptoms/Pathogenicity None until blister forms and toxic fluids result in - a rash accompanied by severe itching nausea vomiting diarrhea dizziness. Secondary bacterial infections of opening are possible. There may be later symptoms--fibrosis of the skin, muscles, tendons and joints ( may interfere with locomotion or use of limbs).

Symptoms On occasion worms migrate to joints , die prematurely, & calcify The calcified worms can trigger arthritis, locked joints, or permanent crippling & deformities

Diagnosis Made by observing visible characteristics of the disease & communicating with the infected person Possible to discover infection up to six months befor emergence Enzyme-linked immunoelectrotransfer Blot (EITB)

Treatment There is no cure. The only treatment is to remove the worm over many weeks by winding it around a small stick and pulling it out a tiny bit at a time. Sometimes the worm can be pulled out completely within a few days, but the process usually takes weeks or months. No medication is available to end or prevent infection. However, the worm can be surgically removed before the wound begins to swell. Antihistamines and antibiotics can reduce swelling and ease removal of the worm

Prevention To stop the infection of the Guinea worm you must keep Guinea worm larvae out of the drinking water. Use only water that has been filtered or obtained from a safe source. Water can be boiled, filtered through tightly woven nylon cloth, or treated with a larvae-killing chemical. People with an open Guinea worm wound should not enter ponds or wells used for drinking water.