(F) Trematodes: Monoecious Trematodes (module-based) Flashcards
- hermaphrodites, leaf-shaped, flattened dorsoventrally
- need two intermediate hosts in their life cycle
Monoecious trematodes
MONOECIOUS TREMATODES
- Releases cercaria
- Metacercaria
- Snail Species
- Infective stage to the definitive hosts
A. 1st Intermediate Host
B. 2nd Intermediate host
ABAB
MONOECIOUS TREMATODES
Eggs laid may either be mature, with embryo called?
miracidium or immature
Enumerate Liver flukes
- FASCIOLA HEPATICA
- OPISTORCHIS FELINEUS
- OPISTHORCHIS VIVERRINI
- CLONORCHIS SINENSIS
- commonly known as the sheep liver fluke
- causes sheep liver rot or fascioliasis hepatica
- has a cosmopolitan distribution but most prevalent in sheep-raising countries
FASCIOLA HEPATICA
FASCIOLA HEPATICA
adult fluke inhabits the?
proximal biliary tracts
in where they rolled like a mat
FASCIOLA HEPATICA
1st and 2nd intermediate host
1st: snail, Lymnea philippinensis
2nd: Nasturtium officinale
FASCIOLA HEPATICA
a watercress which is a species of aquatic flowering plant in the cabbage family.
Nasturtium officinale
FASCIOLA HEPATICA
Diagnostic feature of an Adult
cephalic cone
FASCIOLA HEPATICA
Diagnostic feature of an egg
large, hen’s egg- shaped
Adult
Flat, leaf-like, moderately fleshy with spines on its skin, up to 30 mm x 13 mm, with prominent cephalic cone (diagnostic of the genus) at anterior end.
Ventral sucker slightly bigger than the oral sucker.
Highly branched intestinal ceca extended to the posterior end
Two highly dendritic (or branched) testes, one behind the other at the posterior 3rd and 4th of the body.
Branched vitellaria at the entire lateral side, and a dendritic ovary at the right side of the anterior testis.
Egg
130-150 X 63-90m, large, hen’s egg- shaped (diagnostic feature), ovoid
With broad operculum
Light yellowish brown and immature
when laid
identify
FASCIOLA HEPATICA
FASCIOLA HEPATICA: Pathogenesis, Pathology and Clinical Manifestations
TOF. Metacercaria passing through the intestinal wall does not produce significant pathologic damage.
T
FASCIOLA HEPATICA: Pathogenesis, Pathology and Clinical Manifestations
Parasites traversing the (liver/kidney) parenchyma produce linear necrotic lesion with eosinophils infiltration and hyperplasia of the bile ducts.
liver
FASCIOLA HEPATICA: Pathogenesis, Pathology and Clinical Manifestations
Urticaria may be present, leukocytosis may reach up to how many percent?
60%
FASCIOLA HEPATICA: Pathogenesis, Pathology and Clinical Manifestations
developed because eggs can serve as nidus for stone formation
Gall stone (cholelithiasis)
FASCIOLA HEPATICA: Pathogenesis, Pathology and Clinical Manifestations
due to the temporary lodgment of adult worms in the pharynx, which may happen when a person eats liver of infected animals such as sheep and goats
Halzoun or pharyngeal fascioliasis
FASCIOLA HEPATICA: Diagnosis
Enumerate
- DFS (eggs)
- Duodenal aspirates
- Biliary drainage
FASCIOLA HEPATICA: Pathogenesis, Pathology and Clinical Manifestations
TOF. You can get a true case of fascioliasis if you ingested infected animal’s liver.
F (false)
FASCIOLA HEPATICA: Pathogenesis, Pathology and Clinical Manifestations
How to confirm a person has a false fascioliasis
liver-free diet for 3 days or more and if stool examination showed no eggs, it is likely to be false fascioliasis
FASCIOLA HEPATICA:
Treatment and Control
- Treatment: triclabendazole, nitazoxanide, surgical treatment
- Prevention is through sanitary way of human waste disposal but will not eliminate the parasite due to presence of reservoir hosts such as goats, sheep, and cows. Sanitary protection of watercress beds against the infection should also be considered. Thorough cooking of vegetable will kill metacercaria but may not be accepted as such will change the appearance and nutritional value of the vegetable.
- known as the cat liver fluke is the etiologic agent for opistorchiasis or cat liver fluke infection
- This trematode can be found in Europe mainly in Spain, Italy, Greece, France, Switzerland, Germany, Poland, and Russia.
OPISTORCHIS FELINEUS
OPISTORCHIS FELINEUS
- Bithynia leachi, a species of small freshwater snail
- freshwater or cyprinoid fishes, such as Idus melanotus and Tinca tinca
A. 1st IH
B. 2nd IH
A
B
Adult
7-12 x 2-3 mm, lancet-shaped with smooth cuticle, attenuate anterior, rounded posterior, thin, transparent.
Oral and ventral suckers: nearly of equal sizes.
Simple intestinal ceca, two lobed testes are in oblique position at the posterior part of the worm, small, slightly lobed ovary, transversely compressed vitellaria distributed at the middle 3rd of the body.
OPISTORCHIS FELINEUS
Egg
Elongate ovoid with prominent operculum resting on a prominent rim, appears like an old-fashioned electric bulb (diagnostic)
With a miracidium inside, light yellowish- brown, and with a minute thickening at the posterior part of the shell.
OPISTORCHIS FELINEUS
OPISTORCHIS FELINEUS
Diagnostic feature of an egg
old-fashioned electric bulb
OPISTORCHIS FELINEUS: Pathogenesis, Pathology, and Manifestations
Maturing parasite in the (proximal/distal) bile ducts cause inflammation and proliferative changes in the biliary epithelium leading to fibrosis.
distal
OPISTORCHIS FELINEUS: Pathogenesis, Pathology, and Manifestations
The liver may enlarge and may leads to
passive congestion of the spleen
OPISTORCHIS FELINEUS: Pathogenesis, Pathology, and Manifestations
Bile stones may form around nest of eggs that may lead
cholecystitis (inflammation of gall bladder)
OPISTORCHIS FELINEUS: Pathogenesis, Pathology, and Manifestations
causing engorgement of superficial veins of the abdomen and esophageal varices may develop
Edema and formation of collateral circulation
OPISTORCHIS FELINEUS:
Lab diagnosis
- demonstration of eggs in direct fecal smear or duodenal aspirates
OPISTORCHIS FELINEUS:
Treatment
- Tribendimidine (effective)
- Anti-helminthic drugs (praziquantel, albendazole, and miltefosine)