Trematodes Flashcards
All of these are the snail intermediate hosts of S. mansoni except
a. Oncomelania spp.
b. Planorbis spp.
c. Australorbis spp.
d. Biomphalaria spp.
A. Oncomelania
Oncomelania is the snail I.H for S. japonicum
Other important definitive host of Echinostoma other than humans
Migratory bird
In areas of high prevalence of schistosomiasis, what method is used to reduce morbidity and remains the main control stretegy in the PH?
Mass Chemotherapy
Smallest among blood flukes
S. japonicum
Epigastric pain, nausea &
diarrhea are experienced, especially in the morning
F. buski
Factors that influence the infection of snails BY MIRACIDIA include the following except:
a. age of snails and the miracidia
b. number of miracidia per snail
c. water flow and turbulence
d. length of contact time
NOTC
Chinese vase egg
Paragonimus westermani
This schistosome has inconspicuous/rudimentary
lateral spine/knob
S. japonicum
Parasites with freshwater fish as the 2nd I.H except:
a. Heterophyid flukes
b. Clonorchis sinensis
c. Opistorchis viverrini
d. NOTC
NOTC
How many hours can cercariae survive after release?
24 hours
corresponding to the period from cercarial penetration and schistosomular migration to the time of the flukes mature
incubation
Two general strategies for snail control are:
Focal and Area-Wide
F. buski eggs resemble Fasciola eggs under microscope so, they must be reported as
Fasciolid
Discovered by Philip Garrison
among prisoners of the Bilibid
Prison in Manila,
Echinostoma
spindloid flukes; old electrical light bulb shaped egg shape with one knob at opposite end of operculum; light yellowish-brown shell;
C. sinensis
2nd I.H of Heterophyid flukes
Fishes
✓BALANAK – Mugil spp.
✓TILAPIA – Tilapia spp.
✓KANDULI – Arius manilensis
Snail intermediate host of S. haematobium
Phyopsis spp.
Bulinus spp.
Biomphalaria spp.
Remember: PBB
How many days do schistosomes embryonate and form paired adult worms?
10-12 days
play an important role in the development of young parasites because of their involvement in the metacercarial excystment, tissue invasion, and immune modulation of the host
Cysteine proteases
Common in Sorsogon; often times
misdiagnosed w/ Tuberculosis
Lung fluke (P. westermani)
Specific habitat of S. japonicum
Superior mesenteric vein
Completion of the development of P. westermani in the human body takes how many days?
65-90 days
Added in sputum for paragonimus ova detection which aids for the viscosity
3% NaOH
The only intermediate host of trematodes known to human
Snail
Infective stage of Intestinal flukes
Metacercariae
Standard diagnosis for Blood flukes
Stool examination and rectal imprint (biopsy)
Stages that occurs inside the tissues of the 1st I.H snail except:
a. Miracidia
b. Sporocyst
c. Cercariae
d. NOTC
a. Miracidia
Miracidia is the 1st larva stage that emerges from the egg in FRESHWATER
egg is
larger, golden brown, operculated
A. malayanum
Males have gynecophoral
canal/grooves (where female is held)
Schistosomes
Snail intermediate host of S. haematobium
Phyopsis spp.
Bulinus spp.
Biomphalaria spp.
Remember: PBB
Systemic hypersensitivity reaction to the schistosomulum
migrating through tissue
Katayam disease/Katayama fever/Snail fever
Kahol & Susong pampang are the 2nd snail I.H of this parasite
E. ilocanum
Most important trematode of man because of severity of infection
Schistosomes
oval. thick shelled, yellowish-brown egg, and has a flattened but prominent operculum which has a thickened abopercular portion on the opposite side
P. westermani
How many weeks do F. buski eggs embryonate in water to release miracidium?
3-7 weeks
The only blood fluke that can be diagnosed with urine
Schistosoma haematobium
Intermediate host of S.mansonis
(Snail)
Biomphalaria spp.
Australorbis spp.
Tropicorbis spp.
Planorbis spp.
Best time for the release of cercariae
Early evening to midnight
egg is straw
colored, ovoid
E. ilocanum
Sheep liver fluke
F. hepatica
Hepoptysis is the most common infection of:
Paragonimiasis (P. westermani)
Sporocysts are able to reproduce asexually and can later give rise to free swimming cercariae after how many days?
60-70 days
sample of choice for Shistosomes
Urine, Stool
Trematode w/ similar egg feature w/ cestode’s D.latum
P. westermani
2nd I.H of the oriental lung fluke
Crabs or crayfish
Mode of transmission of F. buski
ingestion of encysted metacercaria from AQUATIC PLANTS
dermatitis due to skin penetration of cercariae from birds &other mammals; common infection from blood flukes
Swimmer’s Itch
Snail intermediate host of S. haematobium
Phyopsis spp.
Bulinus spp.
Biomphalaria spp.
Remember: PBB
They lose their forked tail once they penetrate the host skin and become schistosomulae
Cercariae
2nd Snail I.H of A. malayanum
Lymnaea cumingiana
Ampullarius canaliculatus
Common name of Schistosoma mansoni
Manson’s blood fluke
probably a important reservoir host of echinostosomes
RATS
How many days do miracidium hatch in water do echinostomids?
6-15 days
(operculated with shoulders &small comma-shaped appendage at abopercular end)
C. sinensis
Oriental blood fluke
Schistosoma japonicum
It is currently regarded as the method of choice for definitive diagnosis of schistosoma infections in the Philippines.
COPT (Circumoval Precipitin Test)
In heavier infections:
generalized edema & ascites
occur
F. buski
The following are the second intermediate hosts of F. buski except:
a. water
caltrop
b. water
chestnut
c. water lily
d. Nymphaea lotus
c. water lily
F. buski 2nd I.H
Aquatic Vegetation
Trapa bicornis (water
caltrop)
Eliocharis tuberosa (water
chestnut)
Ipomea obscura (water
morning glory)
Nymphaea lotus
endemic to Korea, China, Taiwan, Vietnam
1st I.H of Heterophyid
Cerithidea, Pirenella (Snail)
Most serious consequence of chronic schistosomiasis
Hepatosplenic schistosomiasis
Schistosome with HEMATURIA or blood in urine as a common pathology
S. haematobium
The following are definitive host of P. westermani except:
a. dog
b. wolf
c. fish
d. monkey
c. fish
Definitive host of P. westermani: man, wolf, fox, tiger, leopard, cat, dog, monkey
most common clinical manifestation observed is consistent peptic ulcer disease; colicky abdominal pain & mucoid diarrhea
Heterophyid flukes
largest intestinal fluke of humans and pigs
F. buski
pear-shaped, thin shell, pale yellow blood fluke egg
S. japonicum
most serious complication of human paragonimiasis
Cerebral involvement
preferred egg counting technique for quantification of schistosoma eggs
Kato-Katz technique
Snail control strategy that requires water contact studies to identify the most common transmission sites
Focal control
3 common types of Schistosoma
Schistosoma japonicum
Schistosoma haematobium
Schistosoma mansori
1st Intermediate host of F. buski
Snail from genus
Segmentina & Hippeutis
Common name of Fasciolopsis buski
Giant Intestinal Fluke
Term for movement of schistosomes which means moving
towards or away from
the source or stimulus
of light
Photactic
Smallest trematode of man;deadliest trematode
Heterophyid flukes (VonSiebold’s)
On the average, a snail sheds only about how many cercariae per day?
2
Associated with presence of eggs in the cervix, vagina and/or
vulva
Female genital schistosomiasis
egg is large, operculated, umembryonated when first passed, & indistinguishable from eggs of F. hepatica & F. gigantica
F. buski
Separate male and female adult worms
Blood fluke
Only trematode with diecious sexuality
Schistosomes
Parasites with aquatic vegetation as 2nd I.H
Fasciolopsis buski
Fasciola hepatica
Fasciola gigantica
This schistosome has Large and prominent terminal spine
S. haematobium
reddish brown; coffee bean shaped adult worm
P. westermani
Requires chest radiography if infection from this parasite worsens
Paragonimus westermani
Infective stage of Schistosomes
cercariae
Enumerate the Life Cycle of trematodes in order
Remember the Mnemonic: Every Man Sends Roses & Candies to Mi Amor
Egg
Miracida
Sporocyts
Rediae
Cercariae
Metacercariae
only trematode that has first and 2nd Intermediate host both as SNAILS
Echinostoma
currently, this group of people have the highest prevalence of being infected w/ P. westermani due to their conservative affinity to traditional dishes
middle-aged Japanese men
Adult worm is a A horseshoe-shaped
collar, bearing one or
two rows of straight
spines, which
surrounds the dorsal
& lateral sides of the
oral sucker
Echinostoma
Common name of Schistosoma haematobium
Vesical blood fluke
Most important liver fluke of man,it is a possible carcinogen
Clonorchis sinensis/Opistorchis viverrini
ingesting raw or insufficiently cooked crabs harboring metacercariae
P. westermani
“snail fever”
Kayatama fever/Katayama syndrome
(may appear
macroscopically in sputum as reddish- brown flecks resembling iron filings; operculated with shoulders & thick
abopercular shell
P. westermani
A newly recognized species that occur only in the lower Mekong River basin
S. mekongi
Life span of Fasciola spp. adult worm
9-13 years
May cause diarrhea with
blood; Heavy infections are
characterized by
inflammation & ulceration
of the intestinal wall.
Echinostoma
The most ‘romantic’ parasite due
to their perpetual copulation
Schistosomes
light brown, ovoid, operculated, fully developed miracidium when laid Old-fashionedlight bulb
Heterophyid flukes
Germ ball egg with triangular
operculum
Echinostoma
Embrayonated eggs from the stool of a definitive host come into contact with fresh water and hatch into free swimming miracidia within how many hours?
2-4 hours
Common foods that could be infected w/ P. westermani except:
a. Kinilaw
b. Kinagang
c. Nam prik poo (crab & chilli paste)
d. Kejang - Korea
NOTC
Common foods that could be infected w/ P. westermani
* Nam prik poo (crab & chilli paste) - Thailand
* Drunken crab - China
* Kejang - Korea
* Ceviche - Peru
* Kinagang, sinugba & kinilaw - Philippines
Arrange the Life Cycle of P. westermani in order
- Cercariae invade the crustacean and encyst into metacercariae
- Embryonated eggs
- Humans ingest inadequately cooked crabs containing metacercariae
- Excyst in duodenum
- Unembryonated eggs
- Adults in cystic cavities in lungs lay eggs which are excreted in sputum. Alternately, eggs are swallowed and passed w/stool
- Miracidia hatch and penetrate snail
- Sporocyst develop from miracidia and become rediae & eventually cercariae
5, 2, 7, 8, 1, 3, 4, 6
Commonname of Echinostoma
Garrison’s fluke
Snail intermediate host of P. westermani are the following except:
a. Antemelania asperata;
b. Antemelania dactylus
c. Brotia asperata
d. NOTC
NOTC
All trematodes have praziquantel as their durg of choice except for fasciola spp. what is their drug of choice?
Triclabendazole
This schistosome has conspicuous lateral spine
(rosethorn)
S. mansoni
group of people who are most susceptible to schistosomiasis
children aged 5-14 yrs old
ingestion of metacercariae encysted in snails the second intermediate host of the parasite
Echinostoma
Where in the Philippines is schistosome most prevalent?
Agusan del Sur
Demonstrates “bleb formation”
Circumoval Precipitin Test (COPT)
refers to the presence of eggs in
the stool resulting not from an actual infection but from recent
ingestion of infected livers containing eggs.
False fascioliasis (pseudofascioliasis)
Arranged the following sequence for Blood fluke’s Life Cycle
- Miracidia penetrate a snail
- Paired adult worms migrate to intestinal veins where they lay eggs
- Cercariae are release in water and penetrate the host skin
- Two generations of sporocyst develop in the snail
- During penetration cercariae become schistosomula and are transported to the liver to mature
- Eggs pass from the host in feces and urine
- Miracidia hatch in water
6, 7, 1, 4, 3, 5, 2
Intermediate host of S. japonicum
Oncomelania hupensis quadrasi
Drug of choice for Blood Flukes
Praziquantel
Specific habitat of S. mansoni
Inferior mesenteric vein
Oriental lung fluke
Paragonimus westermani
Definitive host of F. buski other than humans
Pigs
Mode of Transmission of blood flukes
Skin penetration
The patient experience
generalized toxic & allergic
reactions (edema in the
face, abdominal wall, lower
limbs)
F. buski
The following are common pathology for blood flukes except:
a. Paddy field dermatitis
b. Swimmer’s itch
c. Bloody diarrhea
d. Weight loss
d. Weight loss
A parasite of central & Southeast
Asia (China, Korea, India)
F. buski