Cestodes Flashcards
Describe the general characteristics of Cestodes (Tapeworms).
-flat body
-no alimentary canal
-nutrients absorbed thru tegument
-scolex = head
-stroblia (body) w proglottids (individual repro unit)
-hermaphroditic
-indirect (1 or 2 IH)
Describe the neck & strobila of cestodes.
Neck:
-germinative region & produces segments asexually
Strobila:
-immature proglottids
-mature proglottids
-gravid proglottids
Describe the general characteristics of cestodes.
-adults = sm intestine
-adults = non pathogenic to definitive host (unless alot = obstruction)
-infection site of larvae (metacestodes) = diff w species
-diff types of larval stages (may be pathogenic)
-some are zoonotic
Describe the IH of Cyclophyllidea. (picture)
Compare Order Cyclophyllidea & Order Pseudophyllidea.
Order Cyclophyllidea
-advanced
-1 IH
-scolex, suckers, (+/-) hooks
-eggs = oncosphere w hooks
Order Pseudophyllidea
-2 IH
-scolex & bothria
-egg = oncosphere w cilia
Describe the life cycle of cestodes. (picture)
Describe the IH of Pseudophyllidea.
Fish & crustaceans
-dibothriocephalus latus
-spirometra spp
Describe Dipylidium caninum.
‘flea tapeworms, cucumber tapeworm’ *double pore
-FH = dogs, cats, humans
-zoonotic
-IH = (arthropods) flea, louse
>larval stage (cysticercoid) in IH
-adults in sm intestine
-fresh segment in feces, around anal region, & bedding = cucumber seed
>dry = grain of rice
-fecal float (egg packet, or individual eggs)
-excessive grooming
-adhesive/scotch tape for egg packets
-treat FH w cestocide (praziquantel)
-control IH with insecticide (host + environment)
-PPP = 21 days
Describe the life cycle of Dipylidium caninum. (picture)
Describe Choanotaenia spp & Raillietina spp.
-domestic/wild fowl
-sm intestine
-IH = arthropods (ants, beetles, flies)
>cysticercoid
-IH eat feces of FH that has eggs -> develop into cysticercoid -> IH eaten by FH -> develop into adults in sm intestine
*Choanotaenia spp non pathogenic
*Raillientina spp = reduced growth, emaciation, weakness, decreased egg production
>heavy infection ‘nodular tapeworm disease’ = intestinal granulomas
-eggs dont float well & not diagnostic = necropsy!
-prevent IH in poultry houses
Describe Anoplocephala perfoliata & Anoplocephala magna.
equine cestodes
1. A. perfoliata (common)
-4 cm
-rounded scolex, lappet
-ileocecal valve (partial occlusion)
>intussusception
>colic
*heavy infections = ulcerations, ill health
2. A. magna
-80 cm
-no lappets
-sm intestine
-less pathogenic
BOTH:
-fecal float, sediment, antigen ELISA
-irregular shape (triangular)
-embryo surrounded by pyriform apparatus
-PPP: 1-2mo
-treat w/ praziquantel
-no seasonality
Describe Anoplocephala perfoliata & Anoplocephala magna life cycle.
-gravid proglottids pass in feces -> ingested by oribatid mites -> develop into cysticercoids -> IH eaten by FH
Describe Moniezia spp.
‘Milk tapeworm’
-double pored
-FH = sheep, goat, cattle, other ruminants
-IH = oribatid mites
>infective cysticercoid metacestode
-PPP 1-2mo
-adults 2m
-unarmed (no hooks), scolex w 4 suckers
-segments broader, around anal, in feces = fecal float
-eggs triangle
-non pathogenic
>heavy infection = unthriftiness, GI issue in lamb/goat
-albendazole, praziquantel, niclosamide = weaning treatment
Describe Moniezia expansa VS Moniezia benedeni.
Moniezia expansa = sheep, goats, triangle egg (small)
Moniezia benedeni = cattle, cube egg (larger)
Describe Taenia spp.
-eggs similar (stay in environment)
>striated shell
>sm than toxocara egg
-larval stage = cysticercus
*EXCEPT T. taeniaeformis = strobilocercus
-adults in sm intestine
-non pathogenic
Describe taenia solium life cycle.
Describe echinococcus granulosus general characteristics.
-FH = dogs, canids (fox, dingo)
-IH = herbivores (SHEEP), omnivores & humans (ZOONOTIC - DEH)
-small
-few proglottids
-larval = hydatid in liver, lungs, bones, brains of IH
-adults in sm intestine
-taeniid egg in feces
dog-sheep cycle most IMP
Describe echinococcus granulosus life cycle.
Describe the general characteristics + treatment of echinococcus multiocularis.
Humans = ‘hepatic alveolar echinococcosis’
Canids = ‘echinococcosis’
-cats can be affected but poor hosts
-northern hemisphere
-FH = wild canids (foxes) & domestic dogs
>taeniid eggs in feces
-IH = rodents, lagomorphs, dogs, humans zoonotic
>larvae = alveolar hydatid in liver of IH & metastases of other organs
-adults = <6mm in sm intestine
TREATMENT
-adults = praziquantel (baits for wild canids)
-larval infection in humans/dogs = long term Anthelmintics or surgery
Summary of Echinococcus tapeworms!
Describe mesocestoides spp.
-cyclophyllidea but share some characteristics w pseudophyllidea (ex. Requires 2 IH)
-FH = dogs, cats, humans zoonotic
-IH = 1) arthropod 2) reptile, amphibians, birds, rodents, cats, dogs
-larvae = tetrathyridia
>in body cavities, organs, asexual repro, ingested in meat/organs by FH
-adults = sm intestine
>sucker but no hooks
>400 proglottids (motile) w parauterine organ w egg
-PPP: 2-3wk
Describe dibothriocephalus latus general characteristics.
‘Fish/broad tapeworm’
pseudophyllidea
-FH = fish eating mammals (dogs, cats, bears), humans zoonotic
-IH = 1) copepod infected w procercoid 2) freshwater fish infected w plerocercoid
-bothria = elongated muscular grooves that provide attachment by pinching host tissue
-12m
-square shaped proglottids (3000+) that release 1 mil eggs/day in water
-adults in sm intestine
-larvae in muscles/viscera of fish (plerocercoid)
-PPP: 5-6wk
