Echinococcus granulosus - hydatid cyst

Question 1

What is the causative agent of echinococcosis?

Answer 1

Echinococcus granulosus

Echinococcosis is also known as hydatidosis.

Question 2

What order does Echinococcus granulosus belong to?

Answer 2

Cyclophyllida

Question 3

What are the definitive hosts (FH) for Echinococcus granulosus?

Answer 3

Dog, wolf, jackal

Question 4

What are the intermediate hosts (IH) for Echinococcus granulosus?

Answer 4

Ru, eq, pig, man

Question 5

Where does Echinococcus granulosus locate in the IH?

Answer 5

Lung, liver, heart, brain, bone marrow

Question 6

What is the size range of Echinococcus granulosus?

Answer 6

2-7mm

Question 7

Describe the morphology of Echinococcus granulosus.

Answer 7

2-7mm, scolex with 4 suckers, rostellum with 2 rows with 28-60 hooks, 3-4 proglottids.

Genital pore at the back of the last proglottid, each proglottid has a single pore. Last proglottid is long

Question 8

Where is the genital pore located in Echinococcus granulosus?

Answer 8

Back of the last proglottid

Question 9

What is the life cycle initiation of Echinococcus granulosus?

Answer 9

Gravid proglottids release eggs that are passed in feces

Question 10

What happens after intermediate hosts ingest the eggs of Echinococcus granulosus?

Answer 10

Eggs hatch in the SI, releasing a six-hooked oncosphere that penetrates the intestinal wall and migrates to various organs

Question 11

LC of Echinoccoccus granulosus

Answer 11

1. Gravid proglottids release eggs that are passed in feces. They are immediately infectious.
2. IH ingest eggs, which hatch in the SI and release oncosphere that penetrates the intestinal wall and migrate through the circulatory system into various organs – especially lungs and liver. Develops into a Hydatid cyst. It enlarges gradually, producing protoscolices and daughter cysts.
3. FH gets infected by ingesting the cyst-containing organs in the IH.
4. After ingestion, the protoscolices evaginate and attach to the intestinal mucosa – Develops into adult (takes 32-80 days).
5. Humans are acidental IH, becomes infected by ingesting eggs. Released into the intestine, the hydatid cyst develops in variety of organs. If the cyst ruptures, they can make secondary cysts in other sites.

Question 12

What does the oncosphere of echinococcus granulosus develop into in the intermediate host?

Answer 12

Hydatid cyst

Question 13

How does the definitive host get infected with Echinococcus granulosus?

Answer 13

By ingesting cyst-containing organs from the intermediate host

Question 14

What occurs after the definitive host ingests the cyst (of echinococcus granulosus)?

Answer 14

Protoscolices evaginate and attach to the intestinal mucosa, developing into an adult

Question 15

How do humans become infected with Echinococcus granulosus?

Answer 15

By ingesting eggs

Question 16

Pathogenesis of Echinococcus granulosus?

Answer 16

Silent for years, before it is so enlarged it will cause symptoms.

• Hepatic involvement: abdominal pain, obstruction.
• Pulmonary involvement: chest pain, cough.
• Rupture of cyst: fever, urticaria, Aphylactic shock

Question 17

CS of Echinococcus granulosus?

Question 18

Dx of Echinococcus granulosus?

Answer 18

Flotation method, serological tests, antibody detection

highly infectious material; must be frozen for 7 days at -80 degrees

Question 19

Tx of Echinococcus granulosus?

Answer 19

IH: Surgery and Albendazole
FH: Praziquantel

Question 20

Control of Echinococcus granulosus?

Answer 20

Praziquantel for dogs, vaccination, health education, surveillance of dogs and humans

Question 21

What are the symptoms of pulmonary involvement in echinococcosis?

Answer 21

Chest pain, cough

Question 22

What are the symptoms of hepatic involvement in echinococcosis?

Answer 22

Abdominal pain, obstruction

Question 23

What symptoms can occur if a hydatid cyst ruptures?

Answer 23

Fever, urticaria, anaphylactic shock