Parasitology (Trematodes) Flashcards
Commonly referred as flukes/flatworms
Trematodes
Blood flukes:
Genus Schistosoma
Hosts for Trematodes
Definitive: Man
Intermediate: Snails
Infective stage of blood flukes
Forked tailed cercaria
larva that has mouth, GIT and tail (fork tailed)
Cercaria
MOT for blood flukes
Skin penetration
General characteristics of Blood flukes
Non- hermaphroditic/Dioecious (sexes are separate)
Adult worm is not leaf like, have oral and ventral suckers
Male: short and robust
Female: longer and slender
Eggs are non-operculated
Require only one intermediate and one definitive host
Male worms are provided with ______ to carry female during copulation
gynecophoric canal
Largest Adult Blood Fluke
Schistosoma japonicum
Smallest Adult Blood Fluke
S. mansoni
Appearance:
Integument is with fine tuberculation
S. haematobium
S. japonicum
Appearance:
Integument is rough, and with coarse tuberculation
S. mansoni
Habitat for S. japonicum
Superior mesenteric veins
Habitat for S. mansoni
Inferior mesenteric veins or veins draining rectum
Habitat of S. haematobium
Vesical veins or veins draining the urinary bladder
Blood flukes detected in stool
S. mansoni
S. japonicum
Blood fluke detected in urine
S. haematobium
No. of testes in males of S. japonicum
6-8
No. of testes in S. mansoni
8-9
No. in testes of S. japonicum
4-5
No. of eggs in uterus of S. haematobium
50-100
No. of eggs in S. mansoni
1-4
No. of eggs in S. haematobium
20-30
Intermediate host:
Bulinus, Physopsis
S. haematobium
Intermediate host:
Biomphalaria,
Planorbis and
Tropicorbis
S. mansoni
Intermediate host:
Oncomelania quadrasi
S. japonicum
Eggs:
Non-operculated with distinct terminal spine
Measures 112-170 x 40-70 um
S. haematobium
Eggs:
Non-operculated egg with distinct lateral spine
Measures 45-70 x 140 - 180 um
S. mansoni
Eggs:
Non-operculated, minute lateral spine.
Tissue or red cells.
Size:70 - 105 x 50 -80 um
S. japonicum
Life cycle of Blood Flukes
Eggs → Miracidium → Sporocyst → Circarium → Adult
sac-like larva developed from miracidium
sporocysts