Taeniaisis/Cystercercosis Flashcards
Where are cystercerci located?
In the muscle of intermediate hosts.
What are the important specie of taenia to humans?
T. saginata - beef
T. solium/T. asiatica - pork
What is the difference in distribution of the species?
asiatica is confined to S.E asia whereas the others are found globally.
How do the tapeworms reproduce?
They are hemaphrodites but do cross fertilise each other.
How can the species be distinguished from each other?
T. saginata is not armed whereas the other two are.
What do immature proglottids look like?
They are wider than they are long.
How do the mature proglotids differ?
Mature proglotids are square in shape.
How do gravid proglotids differ?
Rectangular in shape. The genitalia are atropic.
How does motility of the proglotids differ and why is this?
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.
How do the worms get into the muscles of the intermediate host?
They hatch once ingested and the embryos penetrate the intestinal wall before entering the circulation.
What is the name of the cystercercus of:
a) T.saginata
b) T. solium
a) C.bovis
b) C. cellulosae
How is their appearance in the tissues similar/different?
They both have one protoscolex
cellulosae is normally in vesicle form and bovis is a pea sized cyst.
What are the impacts of cystercercosis?
Considerable losses due to mead condemnation
Human health concern.
What are the challenges the cystercercus needs to overcome to get to the definitive host?
Needs to avoid detection in the abattoir and also avoid being killed through cooking.
How long does tapeworm development take?
Around 3 months.
Why is T. solium particuarly dangerous?
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.
Why is santitation very important to aid in control?
A lot of pigs could get infected from a single human source if sanitation is bad.
What are the best methods of control?
General hygeine, properly preparing meat, having good sanitation and meat inspection.
Also managing irrigation water, and carefully preparing fruits and vegetables.
How can tapeworms be identified in humans?
Proglotids or eggs in faeces
Diagnostic imaging for cysts.
How is it diagnosed in pigs & cows?
Tongue test (pigs)
ELISA tests
Meat inspection
What are the chemotherapy options?
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
What are the problems associated with animal management and insepection of meat in controlling the disease?
Management is cost vs. benefit to farmer
Inspection requires enforcement of the rules
What are the impacts of cystercerci in meat?
Complete loss/condemnation
Reduced price (disguise as sausages)
Human illness
What does the scale of the impacts depend on?
Management practices
Processing and marketing of meat
Sewage management
Healthcare provision.
