Blood Trematodes Flashcards
Blood trematodes are under the genus _
Schistosoma
Diseases caused by Blood trematodes
Schistosomiasis / Bilharziasis / snail fever
Known as the oriental blood fluke
Schistosoma japonicum
Difference of schistosomes from other trematodes in the sexual stage
Schistosomes are not hermaphroditic. They have separate sexes
Blood trematodes that supply in the veins of the intestine
S. japonicum & S. mansoni
Blood trematodes that supply the veins of the urinary bladder
S. haematobium
Eggs from schistosoma trematodes are passed in
a. feces
b. urine
c. neither
d. both
d. Both feces and urine.
> urine (S. haematobium); feces (S. japonicum & mansoni)
Distinctive feature of Schistosoma from other species
Spine (sharply pointed terminal spine) to penetrate the vein
Adult location of S. mansoni vs S. japnicum
S. japonicum - small intestine
S. mansoni - large intestine
Resembles the egg of S. haematobium but is acid fast positive
S. intercalatum & guineensis
Resembles the egg of S. mansoni but smaller
S. mekongi
All eggs of Schistosoma are _
Unoperculated & embryonated
Identify:
Pointed terminal spine, unoperculated, embryonated
S. haematobium
Identify:
Small lateral spine, unoperculated, embryonated
S. japonicum
Identify:
Large lateral spine, unoperculated, embryonated
S. mansoni
Intestinal schistosomes have a _ spine
Lateral
Gold standard for the diagnosis of schistosomes
Detection of eggs in feces and urine / rectal biopsy
To optimize recovery of S. haematobium in urine, the specimen should be collected between _
Noon (midday) to 2pm
An 18 y/o male had recently been on 1 month long trip to Brazil with a group of volunteer workers. He complained of crampy abdominal pain, and twice noticed a small amt. of blood in his feces. Microscopic detection showed a large, unoperculated oval egg with large lateral spine. What is the parasite?
S. mansoni
