Trichuris trichiura (whipworm) Flashcards
How is T. trichiura classified?
Metazoa: helminth (nematode)
How is T. trichiura transmitted?
It is a soil-transmitted helminth - a person is infected when contaminated water, food, or soil with embryonated eggs are ingested
What is the life cycle of T. trichiura?
- Embryonated eggs are passed in the stool and get into the soil where they can survive months to years outside of the host
- In the soil, the 2-cell stage develops
- Enter advanced cleavage stage
- Embryonated eggs are ingested by humans and become infective after 15-30 days
- Eggs hatch in the small intestine and release larvae
- Larvae mature in 30-120 days and move extracellular to the colon and cecum (by moving extracellularly)
- The now-adult worms live in the cecum (ascending colon). The adult worms are fixed in this location with the anterior proportion threated into the mucosa (intracellular) and the posterior side is extracellular
- The female begin to lay eggs 60-70 days after infection and shed between 3000 - 20,000 eggs / day. These eggs are passed in feces and this start the cycle again. The lifespan of the adult worms is about a year but can expend to 8 years
- Eggs are sensitive to sunlight, temp <9 >52 degrees
What type of lifecycle has T. trichiura and what type of host is the human?
Direct life cycle
Human - definitive host
What are other reservoirs of T. trichiura besides humans?
soil, chimpanzees, pigs, lemurs, monkeys and humans
What are the symptoms of T. trichiura?
Asymptomatic - light infection
Trichuriasis / Trichuris Dysentery Syndrome (TDS)
- frequent painful bowel movement
- diarrhae + unpleasent smell
Impaired cognitive development in children
rectal prolapse
Where is T. trichiura endemic?
Worldwide, more in tropical araes
How is T. trichiura diagnosed?
Microscopy - detects eggs in stool
PCR
