Intestinal Trematodes

Question 1

Trematodes are also known as _

Answer 1

Flukes

Question 2

Intestinal nematodes are members of the phylum _

Answer 2

Platyhelminthes (flatworms)

Question 3

Lifecycle of Trematodes

Answer 3

1. Eggs in feces/ sputum of humans
2. Miracidium larvae leberated from feces/ sputum and penetrates the snail
3. Develops into redia then cercariae in the snail
4. Metacercaria encysts on vegetation
5. Metacercaria are ingested by humans and excysts in the intestinal tract
6. Back to no. 1

Question 4

Infective stage of trematodes to humans

Answer 4

metacercaria

Question 5

Eggs of F. buski are indistinguishable from _

Answer 5

F. hepatica

Question 6

Largest of the intestinal trematodes

Answer 6

F. buski

Question 7

F. buski is acquired by ingestion of _

Answer 7

Raw water chestnuts or caltrop

Question 8

Heterophyes are indistinguishable from _

Answer 8

Metagonimus yokogawai

Question 9

Food source of infection for Heterphyes and Metagonimus yokogawai

Answer 9

Picked/ uncooked fish

Question 10

A patient complained of a 2 month history of abdominal pain, vomiting, diarrhea, and weight loss. While in africa, she had often eaten the locally grown watercress. A wet mount made during the parasite examination showed large, oval operculated, and unembryonated helminth eggs. What parasite is the most probable cause of the patient’s symptoms

Answer 10

F. buski

Question 11

Difference in the eggs of F. buski, from heterophyes and m. yokogawai

Answer 11

F. buski: operculated, yellow-brown, UNEMBRYONATED

Heterophyes & yokogawai: operculated w/ slight opercular shoulders, yellow brown and EMBRYONATED

Question 12

DOC for treatment of intestinal trematode infection

Answer 12

Praziquantel