Trematodes Flashcards
Larval stages of Digenean Flukes
Egg
1. Miracidium
2. Sporocyst
3. Radia
4. Cercaria
5. Metacercaria
Trematodes acquired by Eating metacercaria encysted on vegetation
Family Fasciolidae
Family Paramphistomatidae
Trematodes acquired by eating a 2nd intermediate host
Family Clinostomidae
Family Dicrocoeliidae
Family Heterophyidae
Family Prosthogonimidae
Family Opisthorchiidae
Family Nanophyetidae
Family Echinostomatidae
Family Paragonimidae
Trematodes acquired by active skin penetration
Family Schistosomatidae
Pathogenicity of Flukes:
Obstruction in Bile ducts and liver cirrhosis
Fasciola, Dicrocoelium
Pathogenicity of Flukes: Gastric and intestinal ulceration leading to hemorrhage
Paramphistomidae,
Heterophyes
Pathogenicity of Flukes: Catarrhal inflammation of pancreatic ducts
Eurytrema pancreaticum
Pathogenicity of Flukes: Laryngopharyngitis
Clinostomum complanatum
Pathogenicity of Flukes: Decalcification and perforation of frontal sinus bone
Troglotrema acutum
Pathogenicity of Flukes: Bronchiolitis and Pneumonia
Paragonimus spp.
Pathogenicity of Flukes: Inflammation of the oviduct and Bursa of Fabricius
Prosthogonimus spp.
Pathogenicity of Flukes: Transmission of Pathogens
Nanophyetes salminocola transmits Neorickettsia helminthoeca
Species of Digenean fluke that does not have a radial stage
Schistosoma japonicum/ Schistosoma spp.
Dicrocoelium dendriticum
Eurytrema pancreaticum
Most common amphistome affecting cattle and carabaos in the Philippines
10-20 mm long and 3-5 mm wide
Egg size: 125-152 μm long, 65-75 μm wide
Fischoederius elongatus
2nd most common amphistome in the Philippines
o Shorter body (8-10 mm long)
o Egg size: 110-120 μm long, 60-75 μm wide
Fischoederius cobboldi
The special integument of parasitic flukes that allows it to withstand the gastric and digestive enzymes of its host.
Syncytial tegument
“true flukes”
“two” ; “generation”
Class Trematoda
Subclass Diginea
Prosthogonimus pellucidus
PS: bursa of fabricius, oviduct and posterior intestine of domestic and wild birds.
IH1: fresh water snail
IH2: dragon fly
DH:fowl, duck, wild birds
Parasites of the bile ducts of carnivores
IH2: are cyprinid fishes
Flat and fusiform-shaped
-Testes(lobed/branched) posterior to ovary, both located on posterior part of body
-vitelline glands : middle lateral fields
Family Opisthorichiidae
the zoonotic agents/parasites are restricted only to vertebrate hosts.
Cyclozoonosis
Excretory tubular network is called?
protonephridia
commonly called the planarians, they are mainly free-living carnivorous flatworms and are of no veterinary significance
Class Turbellaria
flukes that are ectoparasitic to cold-blooded aquatic or amphibious vertebrates and invertebrates, and has a direct life cycle.
Class Monogenea
a parasitic group characterized by the lack of a digestive tract and a body that is segmented into individual reproductive units.
Class Cestoda
A roughly triangular shaped larva, with a broad anterior end
- It is completely covered with cilia
- It possesses and anterior spine at the anterior end, which it uses to bore into the snail IH
- In some species, this (still encased in the egg) must be consumed by the snail.
Miracidium
The ciliated coat is lost upon penetration into the snail IH
It is an undifferentiated mass of cells and therefore does not feed
The germinal cells inside it will multiply and will produce either daughter sporocysts or radiae
Sporocyst
Produced by the radia (or the sporocyst in species with no radial stage)
Cercaria
The final larval stage and is also the infective stage
The encysted form
It has to reach the definitive host in order to complete its life-cycle
Metacercaria
Occurs in the bile ducts of ruminants, especially sheep, cattle, and goat, but can also affect horses, deer, rabbits, humans, cats, dogs, and other mammals.
Adult flukes are leaf-shaped, but broader anteriorly than posteriorly, with an anterior cone-shaped projection
Fasciola hepatica (sheep liver fluke)
less common and almost invariably seen in sheep. It is a traumatic hepatitis with extensive destruction of liver parenchyma and hemorrhage, especially in sheep at 6-8 weeks of age.
Acute fascioliasis
the most common form of infection in sheep, cattle, and other animals (including man). The major consequence of infection if hepatic fibrosis as a result of the migratory tracts produced by the immature flukes in the liver parenchyma, which led to hemorrhage and necrosis
Chronic Fascioliasis
The IH of Family Fascioloides
Lymnea spp. , Lymnea truncata,
Fossaria spp.(F. magna)
Planorbis spp. (F. buski)
Segmentina spp. (F. buski)
they are mainly parasitic in the forestomach of ruminants and the intestines. It also affects pigs, equines, and man. They are thick, conical, and flesh rather than flat.
Family Paramphistomatidae
Fluke that occurs in the large and small intestines of equines, pigs, and warthogs and causes Intestinal ulceration and hemorrhage
Gastrodiscus aegyptiacus (intestinal fluke)
Control and treatment of Fasciolidae Flukes
-Benzimidazole anthelmenthics
-Control of snail intermediate host, best achieved by providing piped water supply to troughs and regular application of a molluscicide
Control and treatment of Paramphistome flukes
-Praziquantel
-Control of snail intermediate host, best achieved by providing piped water supply to troughs and regular application of a molluscicide
Found in the mouth and throat of piscivorous bird (herons, bitterns). Infection has also been recorded in man.
* Cosmopolitan in distribution, but common in Asia and tropical countries
Clinostomum complanatum, C. marginatum
DH, IH, PS and disease of Clinostomum complanatum,
C. marginatum
-DH: Herons, bitterns
-IH1: Lymnea spp., Helisoma spp.
-IH2: fresh water fish
-PS: mouth throat
-Disease: Laryngopharyngitits (birds); yellow grubs (fish)
Describe fasciolidae egg
Brown to yellowish in color, operculum is on blunt end/
describe paraamphistome egg
clear to pale greenish in color, oval shaped, operculum on sharp end.
What is the lesion or injury seen during necropsy that would indicate that a sheep has acute fasciolosis?
Traumatic hepatitis, liver fibrosis
-Parasites of the bile ducts/ pancreatic ducts of ruminants
-2nd IH are terrestrial arthropods
-Flat and lanceolate-shaped
-Testes anterior to ovary, but both are located on anterior half of body
Family Dicrocoelidae
Life Cycle: IH1 produces “slime balls” where the cercariae clump together in the pulmonary chamber of the snail.
Dicrocoelium dendriticum (lancet liver fluke)
Platynosomum fastosum
-DH: cats
- IH1: Sublima snail
- IH 2: Lizard, isopod
- PS: Bile duct, liver
- Disease: Hepatic dysfunction, jaundice, hepatomegaly
Eurytrema pancreaticum
-DH: ruminants
- IH1: snail (Bradybaena, Cathaica)
- IH2: Grosshopper, cricket
-PS: Pancreatic duct
-Disease: Catarrhal inflammation of pancreatic duct
Parasitic in the gallbladder and bile ducts of reptiles, birds, and mammals.
-2nd IH are Cyprinid Fishes
- flat and fusiform-shaped
-Testes(lobed/branched), posterior to ovary.
-reproductive organs: posterior part of the body
Family Opisthorchiidae
Chlonorchis sinensis
“chinese liver fluke”
Ps: Pancreatic duct and bile duct, duodenum
DH: man, dog, weasle, mink
IH1: snail (bulinus, Bithynia)
IH2: Cyprinid fishes
disease: Catarrhal cholecystitis, fibrosis of bile duct, Bile duct occlusion.
Family Opisthorchiidae
Opisthorchis tenuicollis
Opisthorcis viverrini
Chlonorchis sinensis
Ovary anterior to the testes, both located on the posterior end of body. Vitelline glands found laterally but only on posterior half of body
-IH2: fishes
-Ps: small intestines
-DH: canines, felines, man
Family Heterophyidae
Heterophyes heterophyes
PS: small intestine
IH1: snail (Cerithidia cingulata)
IH2: Tilapia
DH: Dog, Man, Cat
Disease: Hemorrhagic diarrhea +. desquamation of intestinal mucosa
Elongate flukes with a strong ventral sucker not far behind the smaller oral sucker (which is surrounded by a ‘head-collar’ that bears a row of spines).
2nd IH are other freshwater snails, tadpoles and freshwater fishes.
-location of the ovary and reproductive organs?
Family Echinostomatidae
-ovary is anterior to testes: both located in middle of body.
1st and 2nd IH of Echinostoma ilocanum
IH 1: Gyraulus, Hippeutis
IH 2:Pila luzonica
Echinostoma revolutum
DH: duck, goose
IH 1 : Lymnea, Planorbis
IH 2: Snail
PS: rectum, ceca
disease: Hemorrhagic or catarrhal enteritis
Parasites of the lungs of carnivores and man
2nd IH are freshwater crabs and crayfishes
Flat and ovoid (lemon-shaped)
Ovary is on one side of the body while uterus is on the other side
Family Paragonimidae
-Paragonimus westermanii
Paragonimus westermanii
DH: Pig, dog,cat, carnivores
IH1: snail
IH 2: crabs, crayfish
PS: lungs (rarely in brain and spinal c.)
Disease: Peritonitis, pleuritis, Chronic bronchioloitis, pneumonia.
Paragonimus kellicotti
DH: Pig, dog,cat, carnivores
IH1: snail
IH 2: crabs, crayfish
PS: lungs
Disease: Peritonitis, pleuritis, Chronic bronchioloitis, pneumonia.
Nanophyetus salmonica
Family Nanophyetidae
DH: dog, cat, fox, cayote, otter
IH 1: snail
IH 2: Salmonid fish
PS: small intestines
disease: Hemorrhagic enteritis, Salmon poisoning
Blood flukes; found in blood vessels, particularly the mesenteric and portal veins.
Dioecious flukes
Family Schistosomatidae
A dermatitis caused by the cercariae of wild waterfowl schistosome when the penetrate and migrate in human skin
Swimmer’s itch
Schistosoma bovis
Family Schistosomatidae
DH: Cattle, ruminants
IH: snail
PS: Portal, mesenteric, urogenital veins
Disease: Serious parasite in cattle and sheep
* Eggs: spindle-shaped (but small ones can be oval)
Schistosoma japonicum
Family Schitosomatidae
DH: Man, cattle, ruminants
IH: snail (Oncomelania quadrasi)
PS: portal and messenteric veins
Disease: Katayama disease
Schistosoma nasalis
DH: ruminnats
IH: snails (Planorbis)
PS: nasal mucosa veins
Disease: Rhinitis, mucopurulent discharge from nose,sneezing, dyspnea and snoring (Snoring Disease)
Ciliated larva with a short free-swimming period in search of a suitable host.
Oncomiracidium
Gyrodactylus elegans
Class Monogenea
DH: Teleost fish (trout)
PS: Skin, fins, gills
Discocotyle sagittata
DH: Salmonid fish
PS: Gills, skin
Class monogenea
Posthodiplostomum cuticula
DH: herons, kingfishers
IH 1: Planorbid snails
IH2: Cyprinid fishes
PS: intestines (DH) ; skin, muscles, eyes (IH2)
disease: Black spot disease (IH 2)
ciliated Larvae of monogenean flukes
Oncomiracidium
