Dracunculiasis (Guinea Worm Disease)
(dra-KUNK-you-LIE-uh-sis)
Dracunculiasis, more commonly known as Guinea worm disease, is a preventable infection caused by the parasite Dracunculus medinensis. Infection affects poor communities in remote parts of Africa that do not have safe water to drink. 

Diagnosis
Treatment
Prevention
Life Cylce
Geographic Distribution

Diagnosis

Signs and symptoms
Infected persons do not usually have symptoms until about 1 year after they drink water contaminated with Dracunculus-infected water fleas.

Fever, swelling, and pain in the area infected by the worm mayd develop a few hours or days before the worm emerges.
More than 90% of the worms appear on the legs and feet, but may occur anywhere on the body.

Ulcers may take many weeks (8 weeks average) to heal; often becoming infected with bacteria. This causes disabling complications, such as locked joints or even permanent crippling. Each time a worm emerges, persons may be unable to work or resume daily activities for an average of 3 months.

Clinical Features:
The clinical manifestations are localized but incapacitating.  The worm emerges as a whitish filament (duration of emergence: 1 to 3 weeks) in the center of a painful ulcer, accompanied by inflammation and frequently by secondary bacterial infection.

A	B

The female guinea worm induces a painful blister (A); after rupture of the blister, the worm emerges as a whitish filament (B) in the center of a painful ulcer which is often secondarily infected.  Images contributed by Global 2000/The Carter Center, Atlanta, Georgia.

Laboratory Diagnosis:
The clinical presentation of dracunculiasis is so typical, and well known to the local population, that it does not need laboratory confirmation.  In addition, the disease occurs in areas where such confirmation is unlikely to be available.  Examination of the fluid discharged by the worm can show rhabditiform larvae.  No serologic test is available.

Treatment
Once the worm emerges from the wound, it can only be pulled out a few centimeters each day and wrapped around a small stick. Sometimes the worm can be pulled out completely within a
few days, but this process usually takes weeks or months. 

No medication is available to end or prevent infection. However, the worm can be surgically removed before an ulcer forms. Analgesics, such as aspirin or ibuprofen, can help reduce
swelling; antibiotic ointment can help prevent bacterial infections. 

Mechanical, progressive extraction of the worm over a period of several days. Traditional treatment of Guinea worm disease consists of wrapping the two- to three-foot-long worm around a small stick and extracting it: a slow, painful process that often takes weeks.

No curative antihelminthic treatment is available.

Prevention

Who is at risk?
Anyone who drinks standing pond water contaminated by persons with Guinea worm infection. People who live in villages where the infection is common are at greatest risk. 

Infection does not produce immunity, and many people in affected villages suffer disease year after year.


Because Guinea worm disease occurs by drinking contaminated water, following these simple preventive measures

• Drink clean water, free from contamination.
• Prevent persons with an open Guinea worm ulcer from entering ponds and wells used for drinking water.
• Filter water fleas from drinking water. See article on filters: nylon in Bull World Health Organ. 1997;75(5):449-52
• Treat contaminated water sources with a chemical, such as Abate*, that kills water fleas.
  
  How the infection occurs. (see also Life Cycle)
  People get infected with Guinea worm disease by drinking water contaminated with Dracunculus larvae. In the water, the larvae are swallowed by small copepods "water fleas." The worms mature inside the water flea and become infective in about 10 days. Once the worms have matured inside the water flea, any person who swallows contaminated water becomes infected. 
  
  Once inside the body, the stomach acid digests the water flea, but not the Guinea worm. During the next year, the Guinea worm grows to full size adult. Adult worms are up to 3 feet long and
  are as wide as a spaghetti noodle. 
  
  After a year, the worm will migrate to the surface of the body. As the worm migrates, a blister develops on the skin where the worm will emerge. This blister will eventually rupture, causing a
  very painful burning sensation. For relief, persons will immerse the affected skin into water. The temperature change causes the blister to erupt, exposing the worm. When someone with a
  Guinea worm ulcer enters the water, the adult female emerges from the wound and releases a milky white liquid containing millions of immature worms into the water, thus contaminating the water supply. For several days after it has emerged from the ulcer, the female Guinea worm releases more immature worms when it comes in contact with water. 

Life Cycle:

Humans become infected by drinking unfiltered water containing copepods (small crustaceans) which are infected with larvae of D. medinensis .  Following ingestion, the copepods die and release the larvae, which penetrate the host stomach and intestinal wall and enter the abdominal cavity and retroperitoneal space .  After maturation into adults and copulation, the male worms die and the females (length: 70 to 120 cm) migrate in the subcutaneous tissues towards the skin surface .  Approximately one year after infection, the female worm induces a blister on the skin, generally on the distal lower extremity, which ruptures.  When this lesion comes into contact with water, a contact that the patient seeks to relieve the local discomfort, the female worm emerges and releases larvae .  The larvae are ingested by a copepod and after two weeks (and two molts) have developed into infective larvae .  Ingestion of the copepods closes the cycle .

Geographic Distribution:
An ongoing eradication campaign has dramatically reduced the incidence of dracunculiasis, which is now restricted to rural, isolated areas in and a narrow belt of 13 African countries: and in a band between the Sahara and the equator. Most cases More than half of all cases of Guinea worm are reported from southern Sudan. Other countries with more than 1,000 cases annually are Nigeria, Ghana, Burkina Faso, Niger, Togo, and Ivory Coast. Smaller numbers of cases are reported from Uganda, Benin, Mali, Mauritania, Ethiopia, and Chad.

Transmission of Guinea worm no longer occurs in several countries, including India, Pakistan, Kenya, Senegal, Yemen, and Cameroon. No locally acquired cases of disease have been reported in these countries in the last year or more.

* Use of trade names is for identification only and does not imply endorsement by the Public Health Service or by the U.S. Department of Health and Human Services.

This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health care provider. If you have any questions about the disease described above or think that you may have a parasitic infection, consult a health care provider.