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For further information, see CMDT Part 35-25: Dracunculiasis
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Essentials of Diagnosis
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Tender cutaneous ulcer and worm protruding from the skin of an individual who has ingested untreated water in rural Africa
Worm death and disintegration in tissue can provoke a severe inflammatory reaction
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General Considerations
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Caused by the nematode Dracunculus medinensis, or Guinea worm
Infection occurs after swallowing water containing the infected intermediate host, the crustacean Cyclops (known as copepods or water fleas)
In the stomach, larvae escape from the copepods and migrate through the intestinal mucosa to the retroperitoneum, where mating occurs
Females then migrate to subcutaneous tissue, usually of the legs, over about a year
A subcutaneous ulcer then forms
Upon contact with water, the parasite discharges large numbers of larvae, which are ingested by copepods
Adult worms, which can be up to a meter in length, are gradually extruded
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Was a major cause of disability; control efforts have been remarkably successful
Annual incidence has decreased from about 3.5 million cases in the late 1980s to 27 reported cases in 2020
All cases were from Chad, Ethiopia, South Sudan, Mali, and Angola
Has been identified in domestic dogs and cats in endemic countries, with dogs likely an important disease reservoir; reported animal cases now outnumber human
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Patients are usually asymptomatic until the time of worm extrusion when a painful papule develops, with erythema, pruritus, and burning
Multiple lesions may be present
A short-lived systemic reaction may develop in some patients and may include
The skin lesion vesiculates over a few days, followed by ulceration
The ulcer is tender, often with a visible worm
The worm is then extruded or absorbed over a few weeks, followed by ulcer healing
Secondary infections, including infectious arthritis and tetanus, are common
Resultant deformities are common with ankle and knee joint infections
Lesions commonly prevent walking for a month or more
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Differential Diagnosis
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Diagnosis follows identification of a typical skin ulcer with a protruding worm
When worm is not visible, larvae may be identified on smears or seen after immersion in cold water
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No drug cures the infection
However, metronidazole and mebendazole are sometimes used to limit inflammation and facilitate worm removal
Corticosteroid ointments may hasten healing
Topical antibiotics may limit bacterial superinfection
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