Platyhelminths 1 Flashcards
2 platyhelminths (flukes) covered?
monogenea & trematoda
monogenea reproduction…
adult worm can produce eggs (oncomiracidia) or young worms
Monogenea morphology…
hermaphroditic (penis, testes, ovary & yolk gland), opisthaptor (area containing hooks & suckers)
Monogenea transmission…
direct contact -> direct lifecycle -> pop. explosions in aquaculture systems -> clinical disease
Monogenea treatment…
sea cage filled with solution of hydrogen peroxide to get rid of skin & gill flukes
3 different monogenean species?
Dactylogyrus spp. Gyrodactylus spp. Benedenia spp.
Dactylogyrus spp. info…
on gills freshwater eggs often resistant to chemical treatment thus weekly treatment over 34 weeks needed
Gyrodactylus spp. info…
skin & fins freshwater live young one treatment adequate
Benedenia spp. info…
affects Kingfish (Aus) affects skin & fins (feed off mucous & epithelial cells) chronic prob. in marine systems difficult to eliminate from system once established
Know general anatomy of trematodes
slide 15
Liver fluke (Fasciola spp.) animals affected?
sheep horse cattle humans others…
Liver fluke (Fasciola spp.) distribution & habitat?
rural temperate & tropical regions every continent! 2.4 million peeps affected (many more at risk)
Liver fluke (Fasciola spp.) human infections in Aus?
very few infections
Liver fluke causing highest economic losses?
F. gigantica ~ 3200 million/year! (Asia & Africa hit hardest)
Liver fluke (Fasciola spp.) most important hosts?
cattle, sheep, buffalo
Liver fluke (Fasciola spp.) lifecycle know well…
slide 20… draw!
Liver fluke (Fasciola spp.) epideiology in Aus…
depends on snail habitats
Coastal & tablelands NSW, All of Vic, Eastern Tassie
Absent in tropics (NT, Nth QLD, Western Aus)
Liver fluke (Fasciola spp.) disease?
Fascioliasis
Acute - blood loss, inflam., abdo. pain, death, black disease
Chronic - Bile duct damage, anaemia, weight loss, bottle jaw, progressive weakness
Liver fluke (Fasciola spp.) diagnosis…
Faecal sample (look for eggs)
Faecal Ag test-ELISA for fasciola antigen in faeces
Liver fluke (Fasciola spp.) prevention & control…
Resistant
Undercooked watercress
Snails
Stomach fluke (Paramphistomes) animals at risk…
Ruminants, cattle, sheep
Stomach fluke (Paramphistomes) special morphological feature…
mouth (stoma) on both sides (amphi)
Stomach fluke (Paramphistomes) lifecycle…
same as Fasciola spp. but no human host. slide 27…
Stomach fluke (Paramphistomes) distribution…
Griffith, NSW
Stomach fluke (Paramphistomes) clinical signs (moderate infection immature fluke)
reduced weight gains
reduced milk production
ill-thrift
Stomach fluke (Paramphistomes) clinical signs (heavy infection immature fluke)
decreased appetite
listlesness
weight loss
foul-smelling diarrhoea -> dehydration -> death
Stomach fluke (Paramphistomes) clinical signs (immature fluke in intestine)
Acute inflammation of the intestine
Death in sever infections
Stomach fluke (Paramphistomes) diagnosis…
post mortem
history of outbreak
clinical signs
response to drenching
examination with magnifying glass -> confirm diagnosis
Stomach fluke (Paramphistomes) why aren’t presence of eggs in manure good diagnostic indicator?
As they only indicate presence of adult fluke and no diagnostic value for an outbreak of the acute disease.
Stomach fluke (Paramphistomes) control…
Draining affected areas.
Fencing off affected areas.
Providing alternative water sources.
Treating stock with drenches effective against stomach flukes
Schistosoma spp. in humans…
S. mansoni
S. hematobium
S. japonicum
Schistosoma spp. geographical distribution…
S. mansoni - Africa & Eastern South America
S. hematobium - Africa
S. japonicum - Far Eastern Asia (near Japan)
Schistosoma spp. lifecycle… draw!
Schistosoma spp. symptoms…
Skin - dermatitis
GI - abdo. pain, diarrhoea, bloody stool -> swollen abdo.
Urogenital - cystitis & urethritis
Schistosoma spp. diagnosis…
History
symptoms
histology
eggs in urine or stool
Schistosoma spp. treatment…
Praziquantel
avoid swimming in snail-infested water
sanitary sewage disposal
eliminate snails
