Taenia solium (1)

Question 1

What are the common names?

Answer 1

Pork Tapeworm

Common name Cysticercosis: Pearly Pork

In humans

 - Taeniosis (Small intestine)
 - Neurocysticercosis (CNS)

Measly Pork

Question 2

What are the final hosts?

Answer 2

Humans

Question 3

What are the intermediate hosts?

Answer 3

Pigs

Humans

Dogs

Mammals

Question 4

Describe adults

Answer 4

3-5 m long

The head (scolex) has 4 suckers and a double row of about 30 hooks

Question 5

Describe larvae

Answer 5

2nd larval stage

 - Cysticercus
 - In muscle

In brain

Pork infected with cysts
- Eggs hatch and the larva penetrate the gut wall and migrate
throughout the body and encyst

Question 6

Describe eggs

Answer 6

Round/oval

25-40 micro m

Thick shelled

Small

Striated

Hexocanth embryo can be seen

Question 7

Explain the life cycle

Answer 7

Eggs passed in feces, ingested by pigs

Cysticercus larvae develop in muscle of intermediate host

FH infected by adult tapeworm ingested in uncooked/undercooked pork (infected)

The adult can grow to more than 3 meters long in the human small intestine and release more than 50,000 eggs per day

Eggs can spread easily and contaminate the soil and water supply

Pig infection
- Free-range pigs become infected by eating human feces
containing tapeworm eggs

Question 8

Describe the distribution

Answer 8

Endemic in pig raising/pork consuming areas

Associated with poverty

 - Inadequate sanitation 
 - Lack of proper slaughtering facilities, meat inspection and control
 - Poor pig husbandry practices

Spread by people/pig movement

 - Immigration
 - Overseas domestic workers
 - International travels
 - Marketing and transport of pigs

Question 9

How does it spread?

Answer 9

Open defecation
- Tapeworm segments come out with feces releasing thousands of
eggs into the environment
- Segments visible in the feces

Question 10

What are the sites of infection?

Answer 10

Intermediate Hosts

 - Muscles
 - Eye
 - Central Nervous System (Brain)
 - Subcutaneous tissue

Final Hosts: Small Intestine

Question 11

Describe the Pathogenesis in pigs

Answer 11

100s-1000s small cysticerci in muscle, heart, brain - Render unfit for
consumption

No clinical signs

Question 12

Describe the Pathogenesis in humans

Answer 12

NCC cases increased

Taeniosis - some discomfort, few clinical signs

Neurocysticercosis (NCC) - ingest oncospheres
- Asymptomatic for years
- Manifests as seizures, severe headaches, neurological problems -
common preventable case of epilepsy
- Can occur in people never around pigs or eaten pork -
consumption of contaminated (human feces) food and water
- Blindness
- Dementia
- Hydrocephalus
- Death

Question 13

How do you diagnose?

Answer 13

Serology (humans/pigs)
- Antibody and antigen ELISA tests and PCR

Lingual exam in live pigs demonstrates cysticerci

Imaging of humans

 - CT
 - MRI

Biopsy subcutaneous nodules

Question 14

How do you treat and prevent?

Answer 14

Anthelmintics

Pig vaccine

Oxfendazole - effective against larval stages in pigs

Good pig husbandry

Preventing pig access to human feces

Strict meat inspection/control

Good hygiene practices

Thorough cooking of pork (people)

Education and training

World effect to eradicate

Question 15

What is important about Taenia solium?

Answer 15

It is ZOONOTIC