Trematodes Flashcards
Order of Trematodes: (4)
- Plagioformes
- Echinostomatiformes
- Opistorchiformes
- Strigeiformes
Describe morphology of Trematodes: (3)
- Unsegmented Bodies
- Dorsal ventrally flattened
- Bilaterally symmetrical
Term for suckers present in Trematodes
Acetabula
This is used for the acquisition of food and nutrients
Oral suckers
This is used for attachment
Ventral suckers
Explain heteroxenous
Requires 2 hosts
Man is never an intermediate host. Man is infected with the larval stage of trematodes.
a. 1st statement is true, 2nd statement is true
b. 1st statement is true, 2nd statement is false
c. 1st statement is false, 2nd statement is true
d. 1st statement is false, 2nd statement is false
b. 1st statement is true, 2nd statement is false
Man is NEVER infected with larval stage.
Species under Echinostomatiformes: (4)
- Fasciola hepatica
- Fasciola gigantica
- Fasciolopsis buski
- Echinostoma ilocanum
Species under Opistorchiformes: (5)
- Opistorchis viverrini
- Opistorchis felineus
- Heterophyes heterophyes
- Metagonimus yokogawai
- Clonorchis sinensis
Schistosoma spp.: (5)
- Schistosoma japonicum
- Schistosoma mansoni
- Schistosoma haematobium
- Schistosoma intercalatum
- Schistosoma mekongi
Fluke that infects the lungs
Paragonimus westermani
Flukes that infect the liver and bile ducts: (3)
- Fasciola hepatica
- Opistorchis spp.
- Clonorchis sinensis
Flukes that infect the intestine:
- Fasciolopsis buski
- Echinostoma ilocanum
- Metagonimus yokogawai
- Heterophyes heterophyes
Blood flukes
Schistosoma spp.
Classification of Trematodes according to sexual differentiation
- Monoecious
- Dioecious
Describe Monoecious: (6)
- Leaflike
- Heteroxenous (3 hosts)
- Operculated, immature eggs
- Infective stage is metacercaria
- Mode of Infection: Ingestion of Metacercaria in 2nd Intermediate host
- Most flukes
Describe Dioecious: (6)
- Cylindrical
- Requires 2 host
- Non-operculated but always matured
- Infective stage is cercaria
- Mode of Infection: Skin penetration
- Blood flukes (Schistosoma spp.)
Explain life cycle of Monoecious flukes
- Eggs will hatch into miracidium which will infect the 1st intermediate host (mollusk).
- Once ingested, this will give rise to a sac-like structure called sporocyst.
- Sporocyst will exhibit asexual reproduction that will produce thousands of Rediae
- Rediae will become cercariae.
- Cercariae will be released from the sporocyst and will become free-living cercariae which will find its 2nd intermediate host.
- Infected 2nd intermediate host will be consumed by man harboring infection.
Explain life cycle of Dioecious flukes
- Eggs hatch into miracidium
- Miracidia infects 1st intermediate host
- Inside the 1st intermediate host, miracidium will develop into sporocyst.
- Sporocyst will become cercaria which will emerge from the 1st intermediate host.
- Free living cercaria will penetrate the skin of the definitive host (man).
Monoecious fluke that infect the lungs and with unique flat operculum and abopercular thickening.
Paragonimus westermani
Other name for P. westermani
Oriental Lung Fluke
Monoecious fluke that is coffee bean-shaped with zigzag intestinal ceca.
P. westermani
Identify:
Paragonimus westermani
1st Intermediate host:
2nd Intermediate host:
Reservoir:
1st Intermediate host: Snail spp.
2nd Intermediate host: Fresh water crustaceans (Crabs, crayfish, shrimp)
Reservoir: Rats, dogs, cats
Pathology of P. westermani
Pneumonia-like/TB-like infection
Hemoptysis (Coughing of blood)
Diagnosis of P. westermani
- Sputum test
- Stool analysis
- Lung biopsy
Sheep liver fluke
Fasciola hepatica
Monoecious flukes that have small operculum, thin shell, and large immature eggs with yellow brown color
Fasciola hepatica
Fasciola gigantica
Fasciolopsis buski
Monoecious flukes that have small operculum, thin shell, and large immature eggs with straw colored eggs
Echinostoma ilocanum
Monoecious flukes that resembles old-fashioned electric bulbs, vase-shaped ova that are already matured.
Opistorchis viverrini
Opistorchis felineus
Heterophyes heterophyes
Metagonimus yokogawai
Clonorchis sinensis
Differentiate the ova of the following:
Heterophyes heterophyes
Metagonimus yokogawai
Clonorchis sinensis
Heterophyes heterophyes - more elongated
Metagonimus yokogawai - broadly ovoidal with smaller knob
Clonorchis sinensis - Thinner shell
Unique characteristic of F. hepatica
Cephalic cone
Describe the intestine of F. hepatica
Branched intestines
Identify:
Fasciola hepatica
1st Intermediate host:
2nd Intermediate host:
Reservoir:
1st Intermediate host: Snail spp.
2nd Intermediate host: Fresh water vegetation (Kangkong, waterlily etc.)
Reservoir: Ruminants, Carabaos, goats
Pathology of F. hepatica
Hepatomegaly
Jaundice
Edema
Diagnosis of F. hepatica
Stool exam
- Direct Fecal Smear
- Kato thick
- Concentration technique
Chinese/Oriental Liver Fluke
Clonorchis sinensis