Trematodes - Cal Flashcards
Trematodes AKA?
Flukes
Two types of suckers on a trematode?
Oral sucker (mouth)
Ventral sucker (acetabulum - “hold-fast” organ)
Most flukes/trematodes are mono or dioecious?
Monoecious
Trematodes usually have two intermediate hosts, which class only has one intermediate host?
Schistosomes
Most trematode ova are operculated. Which class is non-operculated?
Schistosomes
The larval stage of ALL trematodes?
Miracidium
Where does miracidium hatch? What’s a feature of miracidium?
Hatch in water
Miracidium are ciliated
Trematode larval stage that completes development in the snail?
Cercaria
Cercaria characteristics?
larval stage that completes development in the snail
free swimming
Infective form to man (for dioecious/schistosomes)
Encysted cercaria?
METAcercaria
Infective form
Lung fluke?
Paragonimus westermani
TB-like ssx
Fibrosis
Extrapulmonary abscesses
Paragonimus westermani
Paragonimus westermani found?
Asia, N/S America, Africa, India
SOOOO not Europe/Antarctica/Austrlia
How would one go about acquiring the lung fluke? (Paragonimus westermani)
Humans INGEST inadequately cooked/pickled crustaceans containing METACERCARIAE
Paragonimus westermani has two intermediate hosts, which are?
Snail -> Crab/crawfish
Two methods of specimen ID for Paragonimus westermani… Which is preferred?
Sputum preferre (lung fluke, right?)
Feces is also an option
EGGS
Paragonimus westermani egg is oval with what notable feature?
Operculum
Sheep liver fluke?
Fasciola hepatica
Fasciola hepatica mode of infection?
ingestion of metacercariae
Fasciola hepatica diagnosis?
UNembryonated eggs passed in feces
Fasciola hepatica hosts?
Snail -> fresh water vegetation
Specimen of choice for Fasciola hepatica?
eggs
Operculum present, but indistinct
Infected waterplants (watercress?), what you got?
Fasciola hepatica
Fasciola hepatica distribution?
Worldwide
Adults of Fasciola hepatica likely found where in humans?
Bile ducts/liver tissue
Giant intestinal fluke?
Fasciolopsis buski
Biting through the husks of water chestnuts?
Fasciolopsis buski
Fasciolopsis buski ingested in what form?
METAcercariae on WATER plants
similar mode to fasciola hepatica…
Fasciolopsis buski: snail -> aquatic vegetation.. what’s the other trematode with a similar route?
Fasciola hepatica
Fasciolopsis buski: feces is specimen of choice… Their eggs look a lot like?
Fasciola hepatica
Fasciolopsis buski found mostly where?
SE Asia, India, China
Fasciolopsis buski ssx?
As adults in the small intestine, causes diarrhea/blockage of bile duct and intestine
Chinese liver fluke?
Clonorchis sinensis
Cirrhosis/blockage of bile passages?
Cholangitis/pancreatitis… linked to cancer?
Clonorchis sinensis
Clonorchis sinensis found where?
SE Asia, Poland/Russia, Japan, China
Clonorchis sinensis… can become infected how?
Ingestion of fresh water fish containing metacercariae
Clonorchis sinensis habitat? Intermediate host? Reservoir host?
Bile passages of liver
freshwater snail -> freshwater fish (carp, minnows, etc.)
Fish -> piscivores
Clonorchis sinensis specimen of choice?
Feces
BOXER’S GLOVE APPEARANCE
Schistosomiasis AKA?
Bilharzia
Snail Fever
Schistosoma species AKA?
blood flukes
Schistosoma spp… can penetrate in what form?
Cercaria
Snail releases what form of schistosoma?
Free-swimming cercaria that can then penetrate host skin
Two species of schistosoma’s specimen of choice is feces?
Schistosoma japonicum
Schistosoma mansoni
Schistosoma requiring a urine specimen?
Schistosoma haematobium
Schistosoma have no operculum but often contain another notable feature on their egg?
Spine
S. Japonicum spine is lateral/inconspicuous
Spine in s. mansoni is offset
S. haematobium have spine on one end of egg
Most pathogenic schistosome?
S. Japonicum
AKA Oriental blood fluke
S. Japonicum distribution? Habitat?
Far east (duh)
Venules of small intestine
S. Japonicum intermediate host? reservoir host?
Fresh water snail
Mammals (cattle, pigs) exposed to contaminated water
Vesical blood fluke?
S. haematobium
S. haematobium geography?
Pathogenesis?
Africa, ME
Urogenital tract involvement (hematuria, cancer, obstruction)
Conspicuous terminal spine?
S. haematobium
Manson’s blood fluke?
Schistosoma mansoni
Geographic distribution: South and Central America, Cuba, Africa
Schistosoma mansoni
Abdominal pain, cramping, diarrhea, bloody stools
Hepatosplenomegaly, hepatic and intestinal fibrosis, portal hypertension
Schistosoma mansoni
Schistosoma mansoni reservoir host?
Primates, insectivores, wild rodents
Conspicuous, lateral spine?
Schistosoma mansoni
Small intestinal fluke?
Metagonimus yokogawai/Heterophyes heterophyes
Metagonimus yokogawai/Heterophyes heterophyes found?
Far East, Israel, Russia and Spain
Metagonimus yokogawai/Heterophyes heterophyes infective stage?
ingestion of undercooked fish containing metacercariae
Intermediate host
First: Snail
Second: Fish
Reservoir host: Piscivores and birds
Metagonimus yokogawai/Heterophyes heterophyes
similar to clonorchis sinensis
Metagonimus yokogawai/Heterophyes heterophyes specimen of choice?
Ova (similar to clonorchis sinensis)
Too similar too differentiate so clinical diagnosis is necessary
Flukes of the small intestine, cause epigastric distress. Little damage unless heavily infected
Metagonimus yokogawai/Heterophyes heterophyes