Flashcards
Cestodes and trematodes
Cards in this deck (32)
- 1Typical cestode characteristicsAll parasitic
Primarily in the small intestine
Indirect lifecycles with at least 1 intermediate host
Definitive host typically ingests intermediate host - 2Typical cestode morphologyScolex
Neck
Strobila with proglottids
No gut, absorption via tegument - 3Cestode reproductionEach proglottid develops male and female genitals, males first to fertilise eggs of other proglottids. Eggs accumulate in the uterus and are then released into faeces
- 4Typical cestode eggContains a hexacanth embryo (3 pairs of hooks)
Has embryophore (thick coating)
Eggs immediately infective and hatch once consumed. Migrates into the tissues of the intermediate hosts and forms a cyst like structure - 5Types of cestode cystsCysticercus
Cysticercoid
Coenurus
Strobilocercus
Hydatid
Contain one or more protoscolex - 6General characteristics of Taenia genusLive in small intestine of definitive host
Intermediate hist infected via ingesting eggs
Scolex has 4 suckers
1 set of sex organs per segment
Segments release eggs once outside the body, excreted via faeces - 7Taenia ovisDH: dogs
IH: Sheep and goats
Cysticercus in sheep muscle
PPP: 5 week
Treat dogs monthly with cestocidal treatment
Prevent scavenging
Give adequately frozen or cooked meat - 8Taenia hydatigenaDH: Dog small intestine
IH: Sheep
Cysticercus in abdominal cavity that migrates through the liver
Dogs infected by eating offal - 9Taenia taeniaeformisDH: Cats
IH: Rats and mice have strobilocercus in the liver - 10Taenia soliumDH: Human small intestine
IH Pigs, cysticercus in muscle
Cause of neurocysticercosis in humans - 11Taenia saginataDH: Human small intestine
IH: Bovine, cysticercus in muscle - 12Echinococcus granulosusDH: Dog small intestine
IH: hydatids in the liver and lungs of sheep, deer, cattle, pigs, horses and humans - 13Prevention of echinococcus granulosusLimit access to untreated offal
Do not feed offal unless:
-boiled for 30 minutes or frozen at -10 degrees for 10 days minimum
Dispose of carcasses ASAP to prevent scavenging - 14Dipylidium caninumDH: Small intestine of cats and dogs
Cystercercoid in fleas and lice - 15How is genus dipylidium different to taenia?Retractable rostrellum with 6 rows of hooks
2 pairs of gonads per proglottid
Eggs in "packets"
Rounded proglottids - 16Anoplocephala perfoliataDH: Horses, at junction of small and large intestines
Fleshy, small in shape
Cystercercoid in pasture mite
Horse shoe shaped egg - 17Spirometra erinaceiDH in cats and dogs
Infection via ingestion of freshwater crustaceans (IH) or infected lizards, snakes, frogs, rodents, marsupials or pigs (2nd IH)
Ingestion causes sparganosis in humans - 18—Echinococcus granulosus
- 19—Anoplocephala perfoliata
- 20—Dipylidium caninum egg packet
- 21—Anoplocephala perfoliata egg
- 22—Classic cestode egg with hexacanth embryo and embryophore
- 23—Fasciola hepatica egg
- 24—Fasciola hepatica
- 25Characteristics of trematodesUnsegmented
Complex, indirect lifecycles with 1 or many intermediate hosts. Sexual reproduction in DH and asexual in IH.
2 suckers: Anterior is mouth and ventral is attachment - 26Trematode morphologyComplex tegument
Solid parenchyma
Branched, blind ending gut with no anus
Male and female gonads - 27Fasciola hepaticaLeaf life, adults live in the bile ducts of ruminants.
Anterior cone has both anterior and ventral sucker, with genital pore slightly anterior to ventral sucker
Infection via ingestion of metacercariae on pasture that are released from snail
PPP: 8 weeks - 28Intermediate hostLymnaeid genus mud snails
Found in bogs and marsh areas on paddocks
Infection dependent on areas with suitable snail habitats - 29Lifecycle of F. hepaticaAdults feed on GI tract lining, blood and bile
Eggs released in faeces (undeveloped)
Eggs develop in water to a miracidium
Miracidium infects snail, becomes sporocyst
Sporocyst develops into cercariae, motile
Cercariae develops into metacercariae that encysts on vegetation
DH eats metacercariae - 30How does F. hepatica affect the liver?Metacercariae excyst in the SI once eaten, in any mammal that ingests them
They migrate to the liver and penetrate the capsule
They live in the parenchyma
Break into the bile ducts
Mature in the bile duct and release eggs - 31Acute fasciolosisLarge numbers of immature flukes invade the liver simultaneously. Can cause death. Complicated if occuring with concurrent Black disease
- 32Chronic fasciolosisAnaemia and hypoalbuminaemia
Fibrosis of liver parenchyma
Inflammation of bile ducts
Information
- Description
- Infectious disease Flashcards on Cestodes and trematodes, created by Kelly Scott on 13/07/2020.
- Created by
- Kelly Scott
- Views
- 7
- Rating
More on Cestodes and Trematodes