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Syn:
Guinea worm infection ; Medina worm infection.
Eighteen of 20
countries were known in 1986 to have endemic dracunculiasis, i.e.,
Benin, Burkina Faso, Cameroon, Chad, Cote d'Ivoire, Ethiopia, Ghana,
India, Kenya, Mali, Mauritania, Niger, Nigeria, Pakistan, Senegal,
Sudan, Togo, and Uganda.
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Transmission of
the disease in Yemen was documented in 1995, and the World Health
Organization (WHO) declared Central African Republic endemic in 1995.
As of the end of
2004, a total of 16026 cases of dracunculiasis were reported from 12
endemic countries (91% of these cases were reported from Ghana and
Sudan, combined).
WHO has certified
168 countries free of dracunculiasis, including Pakistan (1996), India
(2000), Senegal and Yemen (2004).
Asia is now free
of dracunculiasis.
The disease is caused by the
parasite Dracunculus medinensis, or the guinea worm. It is commonly
referred to as a filaria , but it lacks a microfilarial stage and the
adult worms are distinctly different from the true filariae.
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. (Dr Tsutsumi)
The larvae are
taken up by a freshwater crustacean of the genus Cyclops (water fleas).
They
mature within the crustacean into elongated larvae infective for
humans.
These larvae are liberated by the gastric digestive juices
when a person drinks water contaminated with infected Cyclops (water
fleas).
The larvae migrate through the wall of stomach or small intestine into
the connective tissue of the abdominal wall.
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The male worm is small
and probably dies after copulation. The female worm, which averages I
m in length, wanders out to the subcutaneous tissue, specially that
of the feet and legs.
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A small papule appears, which later becomes a
vesicle with a small ulceration in the center through which the embryo
are liberated.
The latter are usually present in milky fluid
contained in a segment of the worm’s uterus that is extruded and
breaks away from the body of the parasite.
On rare occasions the worms
may be found in joints and serosal cavities.
The signs and
symptoms of dracunculiasis are limited to the period of liberation of
embryos.
Pruritus and moderate edema may be accompanied by low-grade
fever and urticarial rash, caused by an anaphylactic reaction to the
products of the worm.
If the worm dies or if the embryos are liberated
into the tissues, a severe inflammatory reaction with abscess
formation ensues.
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