E3- Helminths Flashcards
What is the causative agent of enterobiasis “pinworm disease”?
Enterobius vermicularis
What is the lifecycle of Enterobius vermicularis?
- Eggs are deposited on perianal region and are then ingested
- Adults mature and gravid females migrate at night to the perianal region to deposit eggs
- Deposited eggs becomes infectious in 4-6 hours
How does a Enterobius vermicularis infection present clinically?
Pruritis ani
How is Enterobius vermicularis dx?
-Tape method to detect the presence of eggs on perianal skin
What is the most effective way to minimize the spread of Enterobius vermicularis?
Handwashing
Which 2 types of nematodes are transmitted via contaminated soil ingestion?
- Ascaris lumbricoides
- Trichuris trichiura
What nematode is known as the “large intestinal roundworm”?
Ascaris lumbricoides
What nematode is known as the “whipworm”?
Trichuris trichiura
What is the lifecycle of Ascaris lumbricoides?
- Infective eggs are ingested
- Larvae travel through the bloodstream to the lungs
- Larvae travel to the mouth where they are swallowed
- Adult worms produce eggs that take weeks to become infectious
What syndrome is a Ascaris lumbricoides infection associated with?
Pulmonary-Loeffler’s syndrome
How is Ascaris lumbricoides dx?
Eggs in stool
What is seen on the morphology of Trichuris trichiura?
- Whiptail
- Egg capsules
What is the lifecycle of Trichuris trichiura?
- Infective (embryonated) eggs are ingested
- Larvae are released and mature into adults
- Adults release eggs
How does a Trichuris trichiura infection present clinically?
- Frequent painful passage of stool
- Rectal prolapse can occur
- Children may suffer growth retardation and anemia
How is Trichuris trichiura dx?
Presence of eggs in stool
Which worms are considered hookworms?
- Necator americanus
- Ancylostoma duodenale
What is the pathophysiology of Necator americanus and
Ancylostoma duodenale?
Feed on blood from intestinal mucosa