Lecture 21: Fluke diseases Flashcards
All trematodes are hermaphrodites except ___
Blood flukes (ex: H. Americana)
Describe the basic life cycle of trematodes
- Eggs are released in DH feces
- Hatch into Miracidia
- Miracidia enter IH (snail)
- Miracidia undergo asexual reproduction in IH and turn into cercariae (infective stage)
- Cercariae are ingested by definitive host or penetrate skin
- Metaccercariae (or cercariae) develop into adult worms in DH
What is the infective stage called in trematodes
Metacercariae
What is the scientific name for common liver fluke
Fasciola hepatic
What disease does F. Hepatica cause
Fascioliasis
Where do adult F. Hepatica worms colonize
Bile ducts
What is the intermediate host for F. Hepatica
Lymnaeid snails
Describe the life cycle of F. Hepatica
- Eggs exit feces of DH
- Miracidia ingested by lymnaeid snails (IH)
- Cercariae develop and are present on vegetation
- Ingested by DH
- Enter duodenum
- Travel to liver
- Adult worms end up in bile ducts
What is acute fascioliasis
Infection of young flukes that parasitize the liver of DH—> cause hemorrhage and inflammation
What are the definitive hosts of F. Hepatica
Herbivores- cattle, sheep, camelids
What definitive host for F. Hepatica is most likely to suffer severe disease
Sheep, can be fatal within 2-6 weeks
Sheep liver that shoes hemorrhage and inflammation, what trematode most likely caused this
F. Hepatica
what trematode is this? Commonly causes liver damage in sheep and cattle. Intermediate host is lymnaeid snails
F. Hepatica
What is chronic fascioliasis
Moderate infection over time that is characterized by presence of adult flukes in bile duct
What clinical symptom is typical of chronic fascioliasis
Bottle jaw
What fecal dx method is used for F. Hepatica
Fecal sedimentation
What drugs tx F. Hepatica
Clorsulon, ivermectin, albendazole
What trematode is this? Commonly infects sheep and cattle. Results in bottle jaw
F. Hepatica egg