Trematodes Lecture Flashcards
Largest trematode infecting humans.
Fasciolopsis buski
Terminal spined eggs are seen in
Schistosoma haematobium
The ova of this parasite resembles an old-fashioned electric bulb and contains a small knob.
Clonorchis sinensis
A term that refers to the parasites that reproduce via separate sexes
Dioecious
General term for (human) infection with flukes
Distosomiasis
Common name of Fasciolopsis buski
Giant Intestinal Fluke
Common name of Fasciola hepatica
Sheep Liver Fluke
All flukes are organ-dwelling except _
Schistosomes
Consumption of infected crab causes human infection with which trematode?
Paragonimus westermani
Which blood fluke is characterized by an egg with lateral spine?
Schistosoma mansoni
T or F. S. japonicum inhabits the superior veins of the small intestine
TRUE
T or F. S. haematobium inhabits the portal vein of urinary bladder.
TRUE
T or F. The male schistosome is more slender than the female.
FALSE
The female schistosome is more slender than the male.
Some Heterophyids have a gonotyl or a genital sucker.
TRUE
Heterophyid adults release embryonated eggs each with a fully-developed miracidium
TRUE
Intestinal Flukes
Fasciolopsis buski
Heterophyes heterophyes
Metagonimus yokogawai
Liver Flukes
Fasciola hepatica
Clonorchis sinensis
Lung Fluke
Paragonimus westermani
Blook Flukes
Schistosoma mansoni
Schistosoma japonicum
Schistosoma haematobium
Heterophyid Flukes
Heterophyes heterophyes, Metagonimus yokogawai
It contains a third sucker (genital or gonotyl sucker)
Heterophyes heterophyes
Common Name for Fasciola hepatica
Sheep Liver Fluke
It has cephalic comb in the anterior end or near the oral socket
Fasciola hepatica
CN for Clonorchis sinensis
Chinese or Oriental Liver Fluke
CN for Paragonium westermani
Oriental Lung Fluke
Most common lung infection in humans
Paragonimus westermani
CN for Schistosoma mansoni
Manson’s Blood Fluke
Schistosoma mansoni inhabits in the ___.
large intestine
CN for Schistosoma japonicum
Blood Fluke
Schistosoma japonicum inhabits in the ___.
small intestine
CN for Schistosoma haematobium
Bladder Fluke
Schistosoma haematobium inhabits the __.
portal vein of urinary bladder
Adult form of trematodes are primarily ___, ___, and ___.
non-segmented
flattened
leaf-shaped
What form of trematodes is the most causing Mostly causing damage or possible irritation and
other pathophysiological mechanisms?
Adult form
Another name for the trematodes
Digenea
Dioecious is specific for what species?
Schistosoma spp.
What trematodes that have presence and location of spines in eggs?
Schistosoma spp.
All trematode eggs are embryonated except?
Fasciola hepatica
Fasciolopsis buski
Echinostoma ilocanum
Paragonimus westermani
They require certain embryonation or developmental period once they are laid.
Underdeveloped eggs
They are capable of developing into another stage of parasite once laid
Embryonated eggs
Infective stage of schistosome
Cercaria
Infective stage of all trematodes except schistosomes
Metacercaria
Stages of Trematodes
Eggs»_space; Miracidia»_space; Sporocyst»_space; Redia»_space; Cercaria»_space; Metacercaria
Characteristics of Trematodes except Schistosome
leaf-like
hermaphroditic
typically food-borne
Characteristics of Schistosomes
long and slender
dioecious
direct penetration of infective stage
What are the specific canals found in Schistosomes males (larger) utilized for copulation with females where they attach themselves until death?
Gynecophoral canal
T or F. All trematode life cycles require a snail as the 1st and/or 2nd intermediate host.
True
T or F. All trematodes are organ-dwelling except schistosomes.
True
Blood-dwelling trematodes
Schistosomes
young form of schistosoma
Schistosomule
T or F. There is no 2nd intermediate host for Schistosoma sp.
True
Specimen of Choice for Trematodes
Feces
Duodenal drainage
Rectal biopsy
Sputum
Urine
It is the most important fluke infecting man
Clonorchis sinensis
Specimen of Choice for Paragonimus westermani
Sputum
Clonorchis sinensis infection is diagnosed through?
EnteroTest
Specimen of Choice for Schistosoma haematobium
Urine
DH of Fasciola hepatica
Sheep, cattle, and other herbivores (humans infected occasionally)
1st IH of Fasciola hepatica
Amphibious snails
2nd IH of Fasciola hepatica
Kangkong (Ipomea obscura), Nasturtium officinale (watercress)
Reservoir Host of Fasciola hepatica
Hares and rabbits, sheep
IS of Fasciola hepatica to DH
Metacercaria
Habitat of Fasciola hepatica
Billiary passages of liver
MOT of Fasciola hepatica
Ingestion of undercooked or raw aquatic plants containing the metacercaria
DH of Fasciolopsis buski
Humans and pigs
1st IH of Fasciolopsis buski
Segmentina or Hippeutis (Segmentina coenosus
Hippeutis cantori)
IS of Fasciolopsis buski
Metacercaria
2nd IH of Fasciolopsis buski
Freshwater vegetation:
Trapa bicornis (water caltrop)
Eliocharis tuberosa (water chestnut)
Ipomea obscura (morning glory or kangkong)
Nymphaea lotus (lotus)
Habitat of Fasciolopsis buski
Duodenum and jejunum (small intestine)
MOT of Fasciolopsis buski
Ingestion of encysted metacercariae from aquatic plants
T or F. Fasciolopsis buski and Fasciola sp. are almost similar under the microscope that is why it is difficult to differentiate
True
T or F. Fasciolopsis buski and Fasciola sp. are almost similar under the microscope that is why it is difficult to differentiate
True
Fasciolopsis buski is commonly found in the ___.
Oriental areas or Far East
Its egg is also described as “Hen’s egg appearance”
Fasciolopsis buski
T or F. F hepatica egg is larger than F. buski egg.
True
Egg contents of F. buski and F. hepatica
Undeveloped miracidium
Eggs of these species have distinct operculum
F. buski and F. hepatica
Adult worm of this trematode is equipped with so-called shoulders (cephalic cone)
Fasciola hepatica
Adult worm of this trematode have large oral sucker
Fasciola hepatica
T or F. Adult worm of Fasciolopsis buski is larger than adult worm of Fasciola hepatica.
True
Adult worm of this trematode has no prominent shoulders (cephalic cone).
Fasciolopsis buski
Adult worm of this trematode has an intestinal ceca that is unbranched or lacks its side branches.
Fasciolopsis buski
Adult worm of this trematode has ventral sucker that is much larger than its oral sucker.
Fasciolopsis buski
Reservoir hosts of F. buski
rabbits, pigs, dogs
F. hepatica has a worldwide epidemiology
True
Adult worm of F. buski and F. hepatica inhabits where?
Small intestine
Metacercariae of F. hepatica and F. buski excyst where?
duodenum
What trematode has clinical manifestations in which the stools are profuse, light yellow in color, and contain much undigested food if there is an heavy infection?
Fasciolopsis buski
T or F. In F. hepatica even light infections may produce signs and symptoms of biliary obstruction and cholangitis due to its size.
True
It is the obstruction or accumulation of adult forms of F. hepatica in the pharynx
Halzoun
DOC for F. buski
Praziquantel
Bithionol (sometimes used)
DOC for F. hepatica
Dichlorophenol (Bithionol)
Triclabendazole
DH of Clonorchis sinensis
Humans and other vertebrates (Cattle)
1st IH of C. sinensis
Snails:
Parafossarulus (P. manchouricus, P. anomalospiralis, and P. stratulus)
Bulinus (B. striatulus)
Semisulcospira Alocinma (A. longicornis)
Thiara (T. granifera)
Melanoides (M. tuberculatus)
2nd IH of C. sinensis
Ctenopharyngodon idellus (Freshwater fish/ Cyprinidae fish)
Freshwater shrimp
IS of C. sinensis
Metacercaria
Habitat of C. sinensis
Liver, bile ducts
MOT of C. sinensis
Ingestion of raw undercooked fish containing the metacercaria
Reservoir hosts of C. sinensis
Sheep, cats, dogs, pigs, other mammals (fish eating animals)
It has old-fashioned bulb in the eggs
Clonorchis sinensis
It has the smallest trematode egg.
Clonorchis sinensis
Egg contents of C. sinensis
Developed miracidium
T or F. C. sinensis egg has operculum.
True
Other features of C. sinensis egg
distinct shoulders
small knob opposite of operculum
It is called as the thickened rim around the operculum in C. sinensis egg.
shoulder
Heterophyes heterophyes and Metagonimus yokogawai eggs resemble what trematode egg?
Clonorchis sinensis egg
What features differentiate C. sinensis egg from H. heterophyes and M. yokogawai eggs?
Small comma shaped process at the abopercular end
Thickened rim around the operculum
Small knob on the opposite end
T or F. Each end of the C. sinensis adult worm is narrower than the midportion of the body.
True
What adult trematode has a spatula-like appearance?
Clonorchis sinensis
What trematode has a ventral sucker that is smaller than the oral sucker?
Clonorchis sinensis
T or F. Clonorchis sinensis has a short intestinal ceca.
False. Clonorchis sinensis has a long intestinal ceca.
Testes of Clonorchis sinensis are what?
dendritic or branching
What trematode has minute vitellaria at the sides?
Clonorchis sinensis
What are located anterior to the testes of Clonorchis sinensis?
A small slightly lobated ovary positioned in the midline and loosely coiled uterus ending at the common genital core
It is responsible for the production of egg shell in C. sinensis.
minute vitellaria
How many flukes should there be to be considered as asymptomatic in C. sinensis?
less than 100
What clinical manifestation results from heavy infections of C. sinensis?
Clonorchiasis
How many phases of pathological changes does clonorchiasis?
4
It results in liver dysfunction in person severely infected over a long period of time by C. sinensis
Cholangiocarcinoma
It is the inflammation of the gall bladder due to C. sinensis.
Cholecystitis
It refers to the gallstone formation due to C. sinensis.
Cholelithiasis
What trematode is sometimes aggravated by the intrahepatic stone formation, cholangitis, and multiple liver abscesses?
Clonorchis sinensis
Cirrhosis is also a possible complication of what trematode?
Clonorchis sinensis
DOC of C. sinensis
Praziquantel
Others:
Albendazole
Artemisinins
synthetic peroxides
What trematode is almost identical to M. yokogawai?
Heterophyes heterophyes
It is considered as the minute flukes.
Heterophyids
CN of Heterophyes heterophyes
Von Siebold’s fluke
DH of Heterophyes heterophyes/ Metagonimus yokogawai
Man, birds, various fish-eating mammals
1st IH of Heterophyids
Brackish water or marine species snails
Pironella
Common 1st IH of Heterophyids in the Philippines
H. taichui
Procerovum calderoni
Melania juncea
Thiara riquetti
2nd DH of Heterophyids
Brackish and salt water fish
tilapia
Mugil cephalus (mullet for H. heterophyes)
IS of Heterophyids
Metacercaria
IS of Heterophyids
Metacercaria
Habitat of Heterophyids
small intestine
MOT of Heterophyids
Ingestion of metacercariae encysted in fish
Egg contents of Heterophyids
Developed miracidium
T or F. Operculum is not present in Heterophyids eggs
False. Operculum is present in Heterophyids eggs.
T or F. Shoulders are present but discrete in Heterophyids eggs.
True
T or F. Small knob is always present in Heterophyids eggs.
False. Small know may be absent in Heterophyids eggs.
Shell thickness of H. heterophyes eggs
Thick
Shell thickness of H. heterophyes eggs
Thick
Shell thickness of M. Yokogawai
Thin
What features differentiate Heterophyids from C. sinensis?
Shoulders are less distinct
Eggs may lack small terminal knob
What trematode have eggs that do not have an abopercular protuberance in contrast to Clonorchis and Opisthorchis eggs?
Heterophyids
T or F. Heterophyid eggs are slightly larger than Metagonimus eggs.
True
Shape of H. heterophyes and M. yokogawai
Pyriform
Adult of this trematode is grayish in color
Heterophyes heterophyes
Adult of this trematode is protected by outer layer of fine scaly spines
Heterophyes heterophyes
Adult of this trematode has tapers at anterior end and round posterior end.
Metagonimus yokogawai
What end of M. yokogawai has a tiny layer of scaly spines?
anterior end
What trematode has avocado or pear shaped with three suckers, having a third sucker which is the gonotyl?
Heterophyids adult
Where is the gonotyl of Heterophyids adults located?
left posterior border of the ventral sucker
T or F. Heterophyids adults have two ovoid testes, variously arranged, are in the posterior end of the body
True
Where is the globular or slightly lobed ovary of Heterophyids located?
submedian, pre- or post testicular area
T or F. Only following anti-helminthic treatments can the adult forms be seen in the feces
True
Heterophyids may escape the intestinal tract and migrate to other areas.
True
Chronic mucous diarrhea and granulomas is a clinical symptom of what trematode?
Heterophyids
What trematode may be encapsulated in the cardiac muscle and may lead to myocarditis or cardiomegaly, resulting in the death of the host due to cardiac arrest?
Heterophyids
A case in Hawaii referred to _______ myocarditis as “mystery death” among Filipino descent due to aberrant ____.
heterophyid; heterophyid eggs
DOC of Heterophyids
Praziquantel
DH of Paragonimus westermani
Dogs, cats, field rats, humans
1st IH of P. westermani
Antemelania asperata (Brotia asperata)
Antemelania dactylus (snail)
2nd IH of P. westermani
Sundathelphusa philippina (Parathelphusa grapsoides; mountain crab or talangka)
Reservoir host of P. westermani
Dogs, cats, field rats, humans, pigs, monkeys
IS of P. westermani
Metacercaria
Habitat of P. westermani
Lungs (encysted in lung tissue)
MOT of P. westermani
Ingestion of uncooked or undercooked crabs
(crustaceans) or crayfish with metacercariae
It is the lung flukes affecting humans in the oriental or Oriental lung fluke.
Paragonimus westermani
What trematode is a zoonotic parasite, meaning humans and animals can serve as definitive and reservoir hosts?
Paragonimus westermani
How many species of the lung fluke belong to the genus Paragonimus?
at least 8
What trematodes are primarily the parasite of wild felines such as canines (dogs, cats, and wolves), civet cats, leopards, lions, tigers, and other mammals?
Paragonimus westermani
T or F. Egg of P. westermani is embryonated at oviposition.
False. Egg of westermani is umebryonated at oviposition.
Egg of this trematode has flattened but prominent operculum.
Paragonimus westermani
Shape of P. westermani egg
somewhat oval
Egg contents of P. westermani
Undeveloped miracidium surrounded by a thin, smooth shell
Other features of P. westermani egg
Prominent operculum with shoulders; obvious terminal shell opposite operculum
What is the color of adult lung fluke?
reddish brown and thick
What adult trematode resembles a coffee bean?
P. westermani
Eggs of P. westermani is discharged into where and they may be expectorated or if swallowed, they may appear in our feces.
bronchioles
T or F. Adult lung fluke is slightly tapered anteriorly.
False. Adult lung fluke is slightly tapered posteriorly
T or F. Tegument of P. westermani adult is covered with single-spaced spines
True
T or F. Tegument of P. westermani adult is covered with single-spaced spines
True
Specimen of Choice for P. westermani
Sputum
T or F. Recovery of eggs in stool is common in P. westermani
False. Recovery of eggs in stool is rare in P. westermani
T or F. Patients with tuberculosis who undergo a sputum exam have a positive result on acid-fast staining, while patients with P. westermani will have eggs on the sputum.
True
Symptoms often mimic those seen in tuberculosis-infected individuals.
Paragonimiasis (pulmonary distomiasis)
It is when P. westermani enters the brain and cause seizures, visual difficulties, and decreased precision of motor skills.
Cerebral paragonimiasis
Sputum of patients with P. westermani is frequently __ and may contain numerous ___.
blood-tinged; dark brown eggs and Charcot-Leyden crystals
Bronchiectasis may result and pleural effusion is
sometimes seen in this trematode?
Paragonimus westermani
It is the most serious consequence of P. westermani in which the flukes enters the cranial cavity through the jugular foramen and invades the brain tissue.
cerebral paragonimiasis
Where does P. westermani enter the cranial cavity?
Jugular foramen
Cutaneous paragonimiasis is a characteristic of what Paragonimus specie?
Paragonimus skrjabini (Paragonimus szechuanensis)
DOC of Paragonimus westermani
Praziquantel
Alternative drug for P. westermani
Bithionol
It is a genus of parasitic blood flukes that infect birds and mammals, including humans
Schistosoma
Fiver medically important blood flukes
S. japonicum
S. mansoni
S. haematobium
S. mekongi
S. intercalatum
Predominant Schistosoma spp in the Philippines
Schistosoma japonicum
Eggs of what Schistosoma spp are found in the feces
S. mansoni
S. japonicum
S. intercalatum
S. mekongi
Eggs of what Schistosoma spp are found in the urine
S. haematobium
T or F. Female worms of Schistosoma spp are shorter than male worms.
False. Female worms of Schistosoma spp are longer
T or F. Male worms of Schistosomes looks cylindrical and have gynecophoral canal where female reposes.
True
T or F. Body structure of schistosomes are particularly long, thick, and seems to clearly have an adaptation to an intravascular existence.
False. Body structure of schistosomes are particularly long, THIN, and seems to clearly have an adaptation to an intravascular existence.
Where do female Schistosomes deposit their eggs after leaving the male worms?
small venules close to the lumen of the
intestine or bladder
What Schistosomes have sharp spines on the eggs that assist in their retention in the blood vessels?
S. mansoni
S. haematobium
T or F. Schistosome eggs are operculated.
False. Schistosome eggs (ova) are not operculated compared to other trematodes and hatch by rupture if liberated into the freshwater.
DH of Schistosoma spp.
Humans
has a wide range of definitive hosts (domestic mammals such as dogs, pigs, cats, carabaos, and cows)
some may be permissive and become infected over an extended period of time and some may be non-permissive wherein schistosomes are stunted or mature but die prematurely
IH of Schistosoma spp.
Snails
require one IH
IS of Schistosoma
Fork-tailed cercariae
Habitat of Schistosoma spp
Mesenteric veins, blood, urinary tract (Schistosoma haematobium)
MOT of Schistosoma spp.
Skin penetration
Redia and metacercaria are not included in its life cycle
Schistosoma spp.
T or F. Only one host is involved in Schistosoma spp.
True
T or F. Adult worms are the cause of Schistosoma spp pathology.
False. Eggs are the cause of its pathology, not adult worms.
Smallest egg among Schistosoma spp.
Schistosoma japonicum
Largest egg among Schistosoma spp.
Schistosoma mansoni
Shape of S. mansoni egg
Oblong
Shape of S. japonicum
Somewhat roundish
Shape of S. haematobium
Somewhat oblong
Egg contents of Schistosoma spp.
Developed miracidium
Appearance and Location of Spine of S. mansoni
Large; lateral
Appearance and Location of Spine of S. japonicum
Small; lateral (difficult to see)
Appearance and Location of Spine of S. haematobium
Large; terminal
What Schistosoma spp egg has a small, knoblike protuberance?
S. japonicum
T or F. Male Schistosomes are shorter but sturdier.
True
What sex of Schistosome has a gynecophoral canal where the longer and more slender sex is held?
Male
What trematode has testes are arranged in one row above the ventral sucker?
Schistosomes
T or F. Female Schistosome has a single pyramidal ovary is located in the midline.
True
Reservoir hosts of Schistosomes
Monkeys, cattle and other livestock, rodents, dogs, cats
It is also called as bilharziasis, swamp fever.
Schistosomiasis
Acute symptoms of Schistosomiasis is more likely to be seen in __.
S.mansoni infections
Petechial hemorrhages may occur at site of penetration of this trematodes
Schistosoma
What stage occurs when Schistosomes reach the mesenteric or vesicular venules and egg laying commences?
Acute stage
T or F. The degree of reaction in Schistosomes is not necessarily proportional to the number of parasites involved.
True
What Schistosomes cause diarrhea or dysentery at acute stage?
S. mansoni
S. japonicum
What Schistosomes cause hematuria (blood in the urine) at the end of micturition and sometimes dysuria (frequent urination)?
S. haematobium
Early symptoms tend to be quite severe in heavily infected persons in this Schistosome spp.
S. japonicum
It is a very common symptom for S. japonicum and often significant mortality rate of the particular stage of the disease.
Katayama fever
Where was Katayama fever first described?
Japan
What eggs of Schistosomes produce most of the pathologic changes seen in chronic schistosomiasis?
eggs in the circulation
It is the most common form of chronic infection in
patients with S.mansoni or S.japonicum.
Hepatosplenic schistosomiasis
Hepatosplenic schistosomiasis also occurs regularly in ___ infections but tends to be subclinical or mild in ___.
S. haematobium; S. japonicum
T or F. In Hepatosplenic schistosomiasis, the chronically enlarged liver is not tender and the spleen may be barely palpable or massively enlarged.
True
Intestinal schistosomiasis is more common in __ and __ infections.
S. mansoni
S. japonicum
It may present a picture suggestive of granulomatous colitis, with abdominal cramps and tenderness, and intermittent bloody mucoid stools.
Intestinal schistosomiasis
Intestinal polyposis is not uncommon in what Schistosome?
Schistosomiasis mansoni
What is the most successful means of
diagnosing this intestinal schistosomiasis?
Colonoscopy
What type of schistosomiasis is seen with S. haematobium infections?
Urinary Schistosomiasis
It is so common among adolescent boys in the Nile River valley as to have been widely considered a phenomenon analogous to the menarche in girls
Hematuria
It is usually the first sign of infection for hematuria.
Terminal hematuria
Squamous cell carcinoma may be found in patients with heavy burden of what Schistosoma spp?
S. haematobium
Nephrotic syndrome is occasionally seen in both what type of Schistosoma spp. ?
S. mansoni
S. haematobium
Pulmonary involvement may be seen in all forms of schistosomiasis but is more common with __ infections.
S. haematobium
It is the coughing of blood due to pulmonary involvement in Schistosoma infections.
Hemoptysis
What trematode has resultant cor pulmonale due to pulmonary involvement of the parasite?
Schistosomes
Cerebral manifestations of schistosomiasis are most
commonly seen in ___ infection.
S. japonicum
What schistosomes affect the spinal cord more than the cerebral?
S. mansoni
S. haematobium
What area of the spine does Schistosome spp usually affect?
Lumbar area
What schistosome has been associated with bladder cancer?
S. haematobium
What schistosome may be associated with repeated Salmonella infections?
S. mansoni
S. japonicum
DOC of Schistosome spp
Praziquantel
It has been used to treat S. mansoni
Oxamniquine
T or F. Antimalarial medications has been proven effective for schistosomes
True
T or F. S. haematobium may damage the
tissues of the bladder causing considerable loss of blood.
True
Drug of choice for treating fascioliasis
Triclabendazole
T or F. Fasciolopsis buski / Fasciola hepatica egg contains undeveloped miracidium.
True
Clonorchis sinensis egg contains undeveloped miracidium.
False
T or F. Heterophyid eggs differ from Clonorchis due to the absence of abopercular protruberance.
True
When the cercaria of S. japonicum shed its forked tail, it becomes a ____.
Schistosomule
This structure in the adult schistosome is where the longer and more slender female is held.
Gynecophoral Canal
