Echinococcus granulosus Flashcards
What type of zoonosis is caused by Echinococcus granulosus
Cyclo-zoonosis
What is the geographical distribution of Echinococcus granulosus?
- World wide
- NOT USA or Carribean
- sheep rearing areas
What are the definitive hosts for Echinococcus granulosus?
-Dogs
-Jackals
-Dingoes
-Wolves
-Coyotes
(any carnivore genus)
What are the intermediate hosts for Echinococcus granulosus?
- Humans
- All herbivores and omnivores
Where does the adult tapeworm of Echinococcus granulosus occur in the definitive host?
-In large numbers in the small intestine
What occurs in all organs of the body due to Echinococcus granulosus infection?
- Hydatid cyst
- Mainly in liver (70% quick) and lungs (20% slow)
How does transmission of Echinococcus granulosus occur?
-Oral ingestion of eggs passed in carnivore feces as proglottids
Do humans pass Echinococcus granulosus eggs?
NO
In regards to the life cycle of Echinococcus granulosus, how does it begin?
- Humans ingest eggs passed in carnivore feces which hatch in gut
In regards to the life cycle of Echinococcus granulosus, what happens after humans ingest eggs?
The mobile embryo (oncosphere) is released from the egg, penetrates the intestinal villi, enters the circulation, and vesiculates within 1-2 days in the liver and lungs.
In regards to the life cycle of Echinococcus granulosus, describe the larval cystic stage(metacestode)
- Develops over months or years in the mature hydatid cysts.
In regards to the life cycle of Echinococcus granulosus, what happens to the cysts in the liver?
They differentiate, degenerate, delaminate membrane, and some become calcified.
What are the clinical symptoms of Echinococcus granulosus?
- Usually asymptomatic besides growth
- prevalence increases with age
- Cyst ruptured may precipitate fatal anaphylaxis
- Cystic Hydatid Disease (CHD): uniocular cysts causes blindness
- Pathognomonic signs (active-transitional-inactive) lamina propria broken down.
What is Cystic Hydatid Disease?
-Uniocular cysts which cause blindness caused by Echinococcus granulosus.
How would one directly diagnose Echinococcus granulosus infection?
- Antigen test using serology
- In dogs: arecoline purgation and coproantigens
