Taeniaisis/Cystercercosis

Question 1

Where are cystercerci located?

Answer 1

In the muscle of intermediate hosts.

Question 2

What are the important specie of taenia to humans?

Answer 2

T. saginata - beef

T. solium/T. asiatica - pork

Question 3

What is the difference in distribution of the species?

Answer 3

asiatica is confined to S.E asia whereas the others are found globally.

Question 4

How do the tapeworms reproduce?

Answer 4

They are hemaphrodites but do cross fertilise each other.

Question 5

How can the species be distinguished from each other?

Answer 5

T. saginata is not armed whereas the other two are.

Question 6

What do immature proglottids look like?

Answer 6

They are wider than they are long.

Question 7

How do the mature proglotids differ?

Answer 7

Mature proglotids are square in shape.

Question 8

How do gravid proglotids differ?

Answer 8

Rectangular in shape. The genitalia are atropic.

Question 9

How does motility of the proglotids differ and why is this?

Answer 9

T.saginata have mobility whereas T.solium do not.

Pigs actively search through faeces but cows will avoid grazing near faeces so the T. saginata proglotids must move away from the faeces in order to be ingested by cows.

Question 10

How do the worms get into the muscles of the intermediate host?

Answer 10

They hatch once ingested and the embryos penetrate the intestinal wall before entering the circulation.

Question 11

What is the name of the cystercercus of:

a) T.saginata
b) T. solium

Answer 11

a) C.bovis

b) C. cellulosae

Question 12

How is their appearance in the tissues similar/different?

Answer 12

They both have one protoscolex

cellulosae is normally in vesicle form and bovis is a pea sized cyst.

Question 13

What are the impacts of cystercercosis?

Answer 13

Considerable losses due to mead condemnation

Human health concern.

Question 14

What are the challenges the cystercercus needs to overcome to get to the definitive host?

Answer 14

Needs to avoid detection in the abattoir and also avoid being killed through cooking.

Question 15

How long does tapeworm development take?

Answer 15

Around 3 months.

Question 16

Why is T. solium particuarly dangerous?

Answer 16

It can form a cyst in human tissues (e.g. the brain), this is only as a result of ingesting a proglotid/egg from infected faeces (poor sanitation). There are some theories that think regurgitation may cause proglotids to move up the GIT in infected humans which could cause the human cystercercosis.

Question 17

Why is santitation very important to aid in control?

Answer 17

A lot of pigs could get infected from a single human source if sanitation is bad.

Question 18

What are the best methods of control?

Answer 18

General hygeine, properly preparing meat, having good sanitation and meat inspection.

Also managing irrigation water, and carefully preparing fruits and vegetables.

Question 19

How can tapeworms be identified in humans?

Answer 19

Proglotids or eggs in faeces

Diagnostic imaging for cysts.

Question 20

How is it diagnosed in pigs & cows?

Answer 20

Tongue test (pigs)
ELISA tests
Meat inspection

Question 21

What are the chemotherapy options?

Answer 21

Niclosamide - adults
Albendazole & pranziquantal - cysts, these damage the parasite skin causing them to disintegrate, however this could lead to seizures and epilepsy so needs to be used with caution in neurocystercercosis.
Oxfendazole for infected animals

Question 22

What are the problems associated with animal management and insepection of meat in controlling the disease?

Answer 22

Management is cost vs. benefit to farmer

Inspection requires enforcement of the rules

Question 23

What are the impacts of cystercerci in meat?

Answer 23

Complete loss/condemnation
Reduced price (disguise as sausages)
Human illness

Question 24

What does the scale of the impacts depend on?

Answer 24

Management practices
Processing and marketing of meat
Sewage management
Healthcare provision.