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:Trichuris trichiura infection ; Whipworm infection ;
Trichocephaliasis.
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Trichuris trichiura (whipworm) is one of the most common intestinal
parasites of humans in tropical areas.
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An estimated
1049 million persons harbour T. trichiura, including 114 million
preschool-age children and 233 million school-age children. The
prevalence of T. trichiura is high and may reach 95% in children in
many parts of the world where protein energy malnutrition and anaemias
are also prevalent and access to medical care and educational
opportunities is often limited.
Mode of
infection:
Trichuriasis is
contracted through the ingestion of food or water containing the ova.
Life cycle:
The larvae are released from the embryonated ova into the small
intestine and become attached to the mucosa.
Subsequently,
they migrate downward to their usual habitat in the ileocaecal region.
The anterior
tip of the whipworm rarely penetrates below the muscularis mucosae,
thus eliciting practically no reaction on the part of the tissues.
Clinical
presentation:
In case of massive infection with T. trichiura , prominent hyperemia
and edema of the mucosa with occasional ulcerations may be produced,
but in the majority of cases the infection does not produce symptoms.
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In severe
cases blood-streaked stools are observed. In the most severe cases
rectal prolapse may occur.
Colonic
obstruction because of a tangle of worms, and perforation have been
reported.
The blood loss
that can occur in T. trichiura infection is likely to contribute to
anaemia, particularly if the child also harbours hookworm, malaria
and/or has a low intake of dietary iron.
Undernutrition
and intestinal parasitic infections affect childhood development and
morbidity in many developing countries. Undernutrition may increase
susceptibility to parasitic infections which in turn impair the
nutritional status of the host.
Rapid, severe
dehydration and concominant electrolyte imbalance may cause death.
Diagnosis of
the disease:
Peripheral eosinophilia is practically never seen in pure Trichuris
infection.
Diagnosis is
made when the characteristic ova are found on stool examination.
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Colonoscopic
study should be considered a useful tool for the diagnosis of T.
trichiura infection, even if no ovum is found in stool examination.
Trichuris
trichiura infection can mimic other forms of inflammatory bowel
disease and lead to physical growth retardation and prolonged
regimens of albendazole may be required for the effective treatment of
massive infestations.
Community
control is important, particularly for the individuals within a
population who harbour heavy worm burdens; this means children, with
special attention to girls who will experience increased iron
requirements and blood loss due to menstruation, pregnancies, and
lactation. Mebendazole and albendazole, both of which are on the WHO
Essential Drugs List, are very effective against T. trichiura ;
multiple doses are needed to attain complete parasitological cure in
all cases. However the goal of control programmes in endemic areas is
morbidity reduction, which follows when intensity of infection is
significantly reduced.
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