Trematodes Flashcards
Name the genus and species of the trematode commonly known as the Chinese Liver Fluke.
Clonorchis sinensis
Name the genus and species of the trematode known as the Sheep Liver Fluke.
Fasciola hepatica.
Name the genus and species of the trematode known as the Lung Fluke.
Paragonimus westermani
This trematode may encyst in the lungs and produce eggs that can be detected in sputum and stool.
Paragonimus westermani
Infections with this trematode are commonly acquired by ingestion of raw or poorly cooked crabs or crayfish.
Paragonimus westermani
This group of trematodes are very difficult to distinguish in the egg stage. You might receive a lab report naming them all.
Clonorchis sinensis – Liver; Opisthorchis felineus – Liver; Opisthorchis viverini – Liver; Metagonimus yokogawai – intestine; Heterophyes heterophyes – intestine
These two trematodes are known as blood flukes, their eggs are found in stool specimens.
Schistosoma mansoni; Schistosoma japonicum;Their eggs are laid in the blood vessels near the intestinal wall, and eventually work their way into the stool.
This trematode is an exception to the “stool for O&P rule”. You want to examine urine to detect this infection.
Schistosoma hematobium
Lack of this intermediate host precludes the establishment of Schistosome infection in the continental U.S.
Species of snail.
Infection with this trematode is acquired by the direct penetration of human skin by the cercariae.
Schistosoma mansoni; Schistosoma hematobium; Schistosoma japonicum
Ingestion of raw or poorly cooked infected fish can lead to infection with this trematode.
Clonorchis sinensis
Ingestion of water plants containing metacercariae can lead to infection with this trematode.
Fasciola hepatica
This trematode dissease is also call bilharzia.
Schistosomiasis
Schistosomes are called blood flukes. The specimens used to diagnose schistosomes are stool and urine. Why don’t we collect blood since the worms live in blood vessels?
Female worms deposit eggs in the portal vessels and perivesical systems. These sharaply barbed eggs are pushed toward the lumen of the intestine (or bladder), break through and eggs sill into urine and fecal flow.
Name schistosome(s) recovered from feces.
Schistosoma mansoni Schistosoma japonicum
Name schistosome(s) recovered from urine.
Schistosoma hematobium
Which schistosome egg has: A: Large lateral spine B: Terminal spine C: Small, inconspicuous spine on lateral surface
A: Schistosoma mansoni has a large lateral spine. B: Schistosoma hematobium has a terminal spine. C: Schistosoma japonicum has an inconspicuous spine on lateral surface.
These members of platyhelminthes (flatworms) penetrate snails and multiply in sporocysts to increase their numbers.
Schistosomes.
Penetration of human skin by ceercariae which are species specific for another host (eg waterfowl) results in a condition known as……
Swimmer’s itch.
True/False: The greatest pathology produced by Schistosoma mansoni is caused by adults consuming the blood of the host.
False. Adults produce many many eggs which are highly antigenic. The human body responds to this antigen and damages tissue. Eggs cut tissue and can lead to secondary bacterial infection. Eggs are the source of pathology.
Gross, visible blood in the urine would cause you to add this parasite to your differential diagnosis.
Schistosoma hematobium
This trematode is commonly known as the lung fluke.
Paragonimus westermani
Ingestion of raw or poorly cooked crabs or crayfish can lead to infectin with this trematode.
Paragonimus westermani
True/False: Lung flukes migrate in the human by flowing along with the bloodstream to the lungs where they settle out and encyst.
False. Immature flukes penetrate into the abdominal cavity, migrate to the lungs by penetrating the diaphragm and mature to adults. They can also migrate to other tissues - brain, muscle, liver, skin, testes, - but eggs can’t pass to the external environment from these sites so the eggs can go undetected.
