Family: Schistosomatidae Flashcards
Scientific Name of blood flukes
Schistosomatidae
Common name of Schistosomatidae
Blood flukes
Schistosomatidae “blood flukes”
• cylindrical
• unisexual
• inhabit the blood vessels
• female is slender and longer, male is much broader
• eggs are non-operculated
• Cercariae are furcocercous
• Cercariae do not encyst
facilitate mating process. female is carried by the male during copulation by means of a ventral groove known as?
gynaecophoric canal
No redia, has 2 generation of sporocyst
Schistosoma japonicum
Final host of Schistosoma
man and domestic animals (ruminants, horse, dog, cat, pig, rabbit and rat)
Intermediate host of Schistosoma japonicum (phil)
Oncomelania hupensis quadrasii
Intermediate host of Schistosoma japonicum (japan)
Oncomelania nosophora
Intermediate host of Schistosoma japonicum (china)
Oncomelania hupensis
Intermediate host of Schistosoma japonicum (Formosa)
Oncomelania formosanum
Concomitant Immunity possible with major escape mechanisms as;
✓ antigenic mimicry
✓ immunosuppression
✓ Isotypic selection
flukes acquire a masking coat of host molecules, thus disguising their non-self character
antigenic mimicry
release of worm-derived neuropeptides
immunosuppression
resistance dependent on balance between protective and blocking effects or specific antibodies
isotypic selection
young flukes
schistosomula
common name of schistosomula
young flukes
Mode of transmission for Schistosomosis
• skin penetration
• ingestion of contaminated water
• prenatal infection
Scientific name of Snail fever, Bilharziasis or Katayama Disease
Schistosomosis
common name of schistosomosis
snail fever, Bilharziasis, katayama disease
Schistosomosis disease has three stages;
- Developmental period
- Period of active oviposition
- Period of proliferation and repair
Developmental period
from skin penetration to mature ova-producing adult worms
• DERMATITIS and PUSTULE FORMATION due to cercarial penetration
• Migration of schistosomula produce pneumonia, nephritis and hemorrhage
Period of active oviposition and extrusion
ulceration and necrosis of the intestine
Period of proliferation and repair
fibrosis
other name of schistosomosis
Bilharziosis
Two clinical syndromes of Schistosomosis
- Acute intestinal syndrome
- Chronic hepatic syndrome
Acute intestinal syndrome
• observed in heavily infected animals
• hemorrhage, edema, and fibrosis in the intestine
• phlebitis of the mesenteric veins
• hemorrhages in the lungs
• clinical signs are PROFUSE, DIARRHEA WITH MUCUS AND BLOOD, DEHYDRATION, PALENESS DUE TO ANEMIA, LOSS OF WEIGHT DUE TO HYPOALBUMINEMIA and ASCITES FORMATION
Chronic hepatic syndrome
• more common in animals; often go unnoticed
• it is an immunologically specific host reaction which results from the presence of eggs in the liver leading to extensive damage and eventuala healing by fibrous tissue formation (granuloma)
• Lymphoid nodules develop around dead parasites in the liver
• Massive thrombosis of the portal veins that lead to hepatic infarction
• presence of ascites
Chronic hepatic syndrome or?
Clay-pipe stem liver fibrosis
drug of choice pf Schistosomosis
Praziquantel
Prevention of schistosomosis
• avoid contact with contaminated water
• proper disposal of human excreta
• destruction of snail intermediate host
• information dissemination
species that affecting humans in mesenteric veins of man in africa, south Africa and the middle east
S. mansoni
species affecting human that eggs laid in the wall of the bladder and urethra
S. hematobium
° Occurs in portal and mesenteric vessels
° Affects ruminants, equine and baboon
° Present in Southern Europe, South Asia and Africa
Schistosoma bovis
with spindle shape eggs
Schistosoma bovis
Intermediate host of Schistosoma bovis
Bulinus sp., Physopsis sp.
found in the veins of the nasal mucosa of cattle, goat, and horse in India
Schistosoma nasalis
eggs are boomerang-shaped
Schistosoma nasalis
Intermediate host of Schistosoma nasalis
Lymnaea sp., Indoplanorbis sp.
causes nasal granuloma “snoring disease”
Schistosoma nasalis
nasal granuloma
snoring disease
occurs in the mesenteric veins of cattle, buffalo, sheep and goat
Schistosoma spindalis
Eggs are flattened on the side with a terminal spine
Schistosoma spindalis
Intermediate host of Schistosoma spindalis
Planorbis spp., Indoplanorbis spp.
Occurs in the portal, mesenteric, pancreatic, hepatic and pelvic vessels of sheep, goat, and cattle, equine and camel in India
Schistosoma indicum
Cause nodule formation in various organs particularly in the liver and pancreas
Schistosoma indicum
Affects pig and dog in India
Schistosoma suis
Eggs are flattened on one side with a small, stout spine
Schistosoma suis
also known as “rice paddy itch”, “hunters itch”, “clam diggers itch”, “cercarial dermatitis”, “sea bather’s eruption”, “lakeside disease”.
Schistosome/Cercarial Dermatitis or “Swimmer’s Itch”
a maculopapular skin eruption caused by penetration of the cercaria of non-human schistosomes into the skin of man producing erythema, pruritus, vesicle formation and marked papule formation (non human)
Schistosome/Cercarial Dermatitis or “Swimmer’s itch”
Incriminated schistosome species are;
Trichobilharzia sp., Austrobilharzia sp., Heterobilharzia
Incriminated schistosome (wild birds)
Trichobilharzia sp.
incriminated schistosome (ducks)
Austrobilharzia sp.
incriminated schistosome (dogs, racoon)
Heterobilharzia sp.
parasites of the bile duct, and pancreatic ducts, of amphibia, reptiles, birds and mammals. Cuticle often lack spines. No redia stage
Dicrocoelidae
where eggs laid
Genital pore
Scientific name of Lanceolate, lancet, or small liver fluke
Dicrocoelium dendriticum
prevalent in tropical region
D. hospes
