Exotic Fluke Infections Flashcards
what are the flukes that have major worldwide importance
- fasciolidae
- dicrocoeliidae
- paramphistomatidae
- schistosomatidae
what is the final host of fasciola hepatica
most mammals
significance in sheep & cattle
what is the intermediate host of fasciola hepatica
galba truncatula
small brown snail
where do the fasciola hepatica adults go in the body
bile ducts of gall bladder
what is the life cycle of liver fluke
when does acute fasciolosis occur
autumn/early winter
how soon after ingestion does acute fasciolosis occur
2-6 weeks post ingestion of high numbers of metacercariae
what is acute fasciolosis caused by
migration of the juvenile flukes
what does acute fasciolosis result in
liver damage
hemorrhage
sudden death
when does subacute fasciolosis occur
late autumn/winter
how soon after ingestion does sub acute fasciolosis occur
6-10 weeks post ingestion of intermediate numbers of metacercariae
what causes sub acute fasciolosis
juvenile migration and adult flukes in bile ducts
what does sub acute fasciolosis result in physiologically
liver damage
hemorrhagic anemia
edema
ascites
when does chronic fasciolosis occur
late winter/early spring
how soon after ingestion does chronic fasciolosis occur
4-5 months post ingestion of low numbers of metacercariae
what does chronic fasciolosis result in physiologically (4)
progressive loss of condition
emaciation
submandibular edema
ascites
what are the epidemiological factors of fasciolosis (3)
- availability of snail habitat
- moisture
- temperature
what is the habitat of the intermediate host of fasciolosis
muddy areas/slow moving water
snails breed may-oct
what increases the snail habitat of fasciolosis
rainfall
increases snail breeding, production of larval stages in snail and egg development
what are the temps for fasciolosis to thrive
mean day/night temp to be >10
how does summer infection of snails occur
how does winter infection of snails with fasciolosis occur
how is acute fasciolosis treated
triclabendazole and move to clean pasture
how is sub acute fasciolosis treated
closantel
nitroxynil
move to clean pasture
how is fasciolosis controled by reducing the snail population
- drainage
- fence off saturated pasture
- move sheep to dry pasture
- molluscicide (none licensed in UK)
- treat and quarantine new arrivals
- treat cattle
where is fasciola gigantica distributed
africa
southern asia
usa (southern and hawaii)
middle east
southern europe
what are the differences between fasciola gigantica and hepatica
fasciola gigantica more pathogenic
intermediate host are aquatic snails
difference in epidemiology
what is the epidemiology of fasciola gigantica
the miracidia hatch at beginning of wet season and infect snails and developed by end of wet season
the cercaria shed from snail at beginning of and during dry season
the metacercaria encyst on aquatic plants or water
when does disease of fasciola gigantica occur
end of dry/beginning of next week
what is the ppp of fasciola gigantica
13-16 weeks
how is fasciola gigantica controlled
similar to f hepatica
snail control
what is the definitive host of fascioloides magna
white tailed deer
what is the impact of fascioloides magna
failure to mature in cattle and sheep
non patent infection
abberant migration in sheep
extensive liver damage
what is the distribution of dicrocoelium dendriticum
worldwide (europe, uk, usa)
what are the main hosts of dicrocoelium dendriticum
sheep
cattle
horses
rabbits
where do the dicrocoelium dendriticum live in the body
bile ducts and gall bladder
what are the intermediate hosts of dicrocoelium dendriticum
land snails/ants
what is the life cycle of dicrocoelium dendriticum
why is dicrocoelium dendriticum called an enslaver parasite
encystation of metacercariae in the ant brain
ant climbs herbage and remains clamping its jaws
increases the chance of transmission
what is the pathogenesis of dicrocoelium dendriticum
heavy infection of older sheep
causes fibrosis of and distended bile ducts
progressive cirrhosis
how does dicrocoelium dendriticum manifest
weakness
anemia
emaciation
loss of production
what is the epidemiology of dicrocoelium dendriticum
intermediate hosts are independent of water
how long do dicrocoelium dendriticum eggs survive
months
how is dicrocoelium dendriticum treated
netobimim (albendazole)
what are rumen flukes
paramphistomatidae
what are the intermediate hosts of paramphistomatidae cervi and microbothrium
aquatic snails
where do the juvenile paramphistomatidae cervi and microbothrium go in the body
excyst in duodenum attach to mucosa and cause pathology
what is the lifecycle of paramphistomatidae cervi and microbothrium
snail stages as fasciola (4 weeks)
metacercaria are ingested
excyst in duodenum where juveniles attach to intestinal wall and feed (6 weeks)
adults migrate to forestomachs
what is the PPP of paramphistomatidae cervi and microbothrium
7-10 weeks
what is the pathogenesis of paramphistomatidae cervi and microbothrium caused by
juvenile intestinal phase of infection attch to duodenal mucosa
causes necrosis and hemorrhage erosion of duodenal mucosa
causes gastroenteritis
what are the clinical signs of paramphistomatidae cervi and microbothrium
fetid diarrhea
anemia
hypoalbuminemia
intense thirst and anorexia
how is paramphistomatidae cervi and microbothrium diagnosed
post mortem – juveniles in duodenum
fecal egg count of limited value
how is paramphistomatidae cervi and microbothrium treated
oxyclozanide
what are the intermediate hosts of schistosomatidae
aquatic snails
what is the distribution of schistosomatidae
tropics
sub tropics
southern europe
what is the lifecycle of schistosomatidae
what is the pathogenesis of schistosomatidae
inflammatory response against eggs in veins, mucosa and liver leading to granuloma formation intestinal mucosa and liver
what does acute schistosomatidae cause
mucosal hemorrhage
anemia
hypoalbuminemia
hepatosplenomegaly
what are the clinical signs of schistosomatidae
anemia
diarrhea – mucus and blood tinged
thirst
anorexia
emaciation
what does chronic schistosomatidae cause
marked granuloma of intestine and cirrhosis/periportal fibrosis of liver
reduced productivity
how is schistosomatidae diagnosed
clinical signs
infected water source
granulomatous lesions and adults in mesenteric veins
eggs
how is schistosomatidae controlled
clean water source
praziquantel
albendazole
