Platyhelminthes 3 Flashcards
Trematodes description
Flukes
Oval or leaf-like body
Few mm to few cm long
Tegument with spines
Reproductive system of treamtodes
Hermaphodites - reproductive system occupies most of the body
Life cycle of trematodes
Complex, molluscs as intermediate hosts
Fasciolosis general description
Fasciolosis is a parasitic disease caused
by the common liver fluke from the
family Fasciolidae, which occurs
mainly in ruminants and is common in
moist, swampy areas. The course of
the disease is acute or chronic.
Intermediate and final host(s) of Liver fluke
Final hosts: ruminants (others might be reservoirs)
Intermediate host: mud-snail
Liver fluke in latin
Fasciola hepatica
(F. gigantica)
Liver fluke: distribution
Worldwide, seasonal outbreaks (heavy rainfall in summer –> more snails)
Liver fluke: habitat in final host
Bile ducts in the liver
Liver fluke: transmission
Ingestion of parasite larva (metacercaria) from plants
Liver flukes pathogenesis
Two-fold pathogenesis:
Young parasite: migration causes damage to liver and blood vessels
Adult parasite: in the bile duct; cause biliary mucosa damage and ingest blood –> anemia
Chronic disease: cirrhosis, thickened bile ducts
In sheep: bottle jaw neck very common clinical sign! (submandibular oedema)
Liver fluke: diagnostic methods
-Fecal sedimentation (no eggs in acute fascioliosis)
-Bloodwork: raised liver enzymes, serology for herd screening
-Necropsy - parasites in bile ducts, liver, gallbladder
Liver fluke egg description
Shape: ellipsoidal
Content: granular, larva inside
Shell: thin
Colour: yellow brown
Liver fluke: prevention
Reduction in snail populations
Fencing in snail habitats
Liver flukes differences in seasons
Early autumn: acute disease and sudden deaths
Early spring: cronic disease
Liver fluke: zoonosis?
Yes, can be
Paramphistomiosis is what?
Rumen fluke infection
General description of paramphistomiosis
Paramphistomosis is a parasitic
disease caused by the young forms
that migrate in the mucosa of the
small intestine and forestomach of
ruminants, and by the adults that
attach to the wall of the foregut. The
disease is common in moist pastures.
Rumen fluke in latin
Paramphistomum cervi
Rumen fluke/Paramphistomum cervi
Final and intermediate host(s)
Final hosts: ruminants, wild cervids
Intermediate host: aquatic snail
Rumen fluke/Paramphistomum cervi
Morphology
Non-typical trematode: conical and maggot-like, adults pear-shaped
Size: juveniles 1-3mm, adults up to 15mm
Color: juveniles pink, adults brownish
Rumen fluke/Paramphistomum cervi
Epidemiology
More prevalent in tropical regions
Moist swampy pastures
More at the end of rainy summer
Rumen fluke/Paramphistomum cervi
Place inside host
Adults: forestomach
Juveniles: duodenum
Rumen fluke/Paramphistomum cervi
Transmission
Ingestion of plants with larvae (cercaria)
Rumen fluke/Paramphistomum cervi
Life cycle
Similar to liver fluke
Rumen fluke/Paramphistomum cervi
Pathogenesis and clinical signs
Parasite burrows into mucosal and submucosal layers causing necrosis and hemorrhage
Clinical signs rare, seen in young cattle with heavy infection
Enteritis, diarrhea, anorexia, polydipsia, unthriftiness, oedemas
Rumen fluke/Paramphistomum cervi
Diagnostic methods
Fecal sedimentation (no eggs in acute disease)
Necropsy
Dicrocoelosis general description
Dicroceliosis is a chronic parasitic
disease caused by a small lancet fluke
that parasitizes mainly in the bile
ducts and gall bladder of ruminants,
and is common in hilly and dry
pastures.
Small lancet fluke, latin name
Dicrocoelium dendriticum
Dicrocoelium dendriticum
/small lancet fluke
Final and intermediate host(s)
Final hosts: mainly ruminants, occasionally others
Intermediate hosts:
1 - land snail
2 - brown ant
Dicrocoelium dendriticum
Geographical distribution, habitat, transmission
Geography: worldwide
Habitat: biliary and pancreatic ducts
Transmission: ingestion of metacercaria in ants
Dicrocoelium dendriticum
Life cycle
Egg hatches inside snail
Snail produces slime balls with larvae
Ants ingest larvae
Larvae develops inside ant
Host eats ant
Young flukes migrate from small intestine into bile ducts
Dicrocoelium dendriticum
Pathogenesis and clinical signs
Liver damage only in severe cases (cirrhoses, fibroses), usually no or small damage because there’s no parenchymal migration
Does not suck blood
Clinical signs usually absent
In older sheep, alpacas, llamas:
Anemia, oedema, hypothermia, emanciation, weight loss etc
Dicrocoelium dendriticum
Diagnostic methods
Feacal flotation
Sedimentation
Necropsy
Dicrocoelium dendriticum egg morphology
Shape: asymmetrical oval, operculum
Content: larva
Shell: thick
Color: dark brown
Dicrocoelium dendriticum
Prevention
Difficult to control because:
-eggs survive well (also in drying of hay)
-wide distribution of the intermediate hosts
-many reservoir hosts
Dicrocoelium dendriticum, zoonosis?
Yes. Don’t eat ants.
Cat liver fluke is called?
Opisthorchis felineus
Opisthorcis felineus
Final and intermediate host(s)
Final hosts: humans, dogs, cats
Intermediate hosts;
1. freshwater snail
2. freshwater fish
Opisthorchis felineus
transmission
Eating raw fish
Opisthorchis felineus
Distribution, location in host
Worldwide, endemic in many european countries
Biliary or pancreatic ducts, small intestine
Opisthorchis felineus
Clinical signs
Mild to severe, chronic
Epithelial hyperplasia
Fibrosis
Carcinomas in liver/pancreas
Cholecystitis
Diarrhea or constipation
Opisthorchis felineus
Diagnostic methods
Fecal sedimentation
Alariosis general description
Alariosis is a parasitic disease in the
small intestine of carnivores, caused
by worms of the genus Alaria, in which
gastro-intestinal inflammation and
lung damage occur.
Alariosis pathogen
Alaria alata
Alaria alata hosts
Definitive hosts: wolves, foxes, dogs
Intermediate hosts:
1. IM hosts: freshwater snails
2. IM hosts: tadpoles
Reservoir hosts: snakes, mice, birds
Dead-end hosts: humans
Alaria alata in host
Small intestine
Young flukes migrate to diaphragm,
lungs - pulmonary haemorrhages
