Cestode: Beef Tapeworm

Question 1

What are oncospheres?

Answer 1

tapeworm embryos

Question 2

What is cysticercus?

Answer 2

Stage/form of worm in animal tissue (infectious larvae cyst)

Question 3

Explain the life cycle of the beef cestode

Answer 3

Eggs in feces are eaten by intermediate host (pig, cow – from the environment) Intermediate host carries cyst (larvae - CYCTICERCUS) in tissues (muscle)

• Cysts in animal muscle consumed by another animal or by infected animal leading to re-infection
• Human with adult worms in GI tract
• Worms can attach to intestine or penetrate

Question 4

What are the clinical manifestations of beef cestode?

Answer 4

• majority are asymptomatic
• sometimes non-specific epigastric discomfort
• proglottids may climb through anus

Question 5

In what countries is the Beef Tapeworm (Cestode) most common?

Answer 5

Central Asia, East Africa, Central and South American, Near East

Question 6

How is the beef cestode transferred to humans?

Answer 6

Beef cestode is spread to humans by consumption of cyst-infected uncooked beef

Question 7

How do you diagnose Beef Tapeworm?

Answer 7

Examine stool – proglottids are motile (can “climb” through anus).

• Patient may pass entire worm (5-6 meters long)
• Cow proglottids are longer (lab knows this)
• Eggs in feces - both cow and pig look the same – just treat
• No eosinophilia
• Multiple exams may need to be performed as egg and proglottid release is sporadic

Question 8

How do you treat beef tapeworm (cestode)?

Answer 8

Look it up and punt

Question 9

How do you prevent infection by beef cestode?

Answer 9

• Cook beef at 56 deg x 5 min. ????
• Freeze - 5-10 days
• Sanitation to prevent cattle infection