(roundworm) Trichuris trichiura, also called the human whipworm.
eggs are passed with the stool
In the soil, the eggs develop into a 2-cell stage
an advanced cleavage stage
and then they embryonate
eggs become infective in 15 to 30 days. After ingestion
(soil-contaminated hands or food), the eggs hatch in the small
intestine, and release larvae
mature and establish themselves as adults in the colon
The adult worms (approximately 4 cm in length) live in the cecum and
ascending colon. The adult worms are fixed in that location, with the
anterior portions threaded into the mucosa. The females begin to
oviposit 60 to 70 days after infection. Female worms in the cecum shed
between 3,000 and 20,000 eggs per day. The life span of the adults is
about 1 year.
third most common round worm of humans. Worldwide, with infections more
frequent in areas with tropical weather and poor sanitation practices,
and among children. It is estimated that 800 million people are
infected worldwide. Trichuriasis occurs in the southern United States.
frequently asymptomatic. Heavy infections, especially in small
children, can cause gastrointestinal problems (abdominal pain, diarrhea,
rectal prolapse) and possibly growth retardation.
Microscopic identification of whipworm eggs in feces is evidence of
infection. Because eggs may be difficult to find in light infections, a
concentration procedure is recommended. Because the severity of
symptoms depend on the worm burden, quantification of the latter (e.g.
with the Kato-Katz technique) can prove useful.
comparison with other intestinal parasites
Examination of the
rectal mucosa by proctoscopy (or directly in case of prolapses) can
occasionally demonstrate adult worms.
Mebendazole is the
drug of choice, with albendazole as an alternative.