Zoonotic Disease- Parasites
Card Set Information
Zoonotic Disease- Parasites
What stage of Toxocara canis poses a zoonotic risk?
larval stages that undergo somatic migration, larvated eggs
Which roundworms of dogs and cats are zoonotic?
Toxocara canis, Toxocara cati, Baylisascaris
A potential consequence of nematode infection in humans.
ocular larval migran- blindness
What are zoonotic characteristics of roundworms? (3)
are not infectious in freshly passed feces, pups/kittens infected at birth, once infectious difficult to destroy
Baylisascaris infects ________.
Baylisascaris infects young by ____________; it infects older animals by ______________.
ingestion of eggs; ingestion of L3 in rodents
What roundworm has resistant eggs?
What domestic species can serve as a DH for Baylisascaris?
When Baylisascaris undergoes somatic migration (NOT in raccoon), larvae...
get bigger and bigger as they migrate.
How do you kill the resistant eggs of Baylisascaris?
boiling water, blow torch
What are the consequences of larval migration of Baylisascaris? (5)
larvae get bigger and bigger, mechanical damage, tissue necrosis, granulomatous inflammation, eosinophils
How do you prevent roundworm infections?
toxocara: deworm, pick up fresh feces; baylisascaris: avoid raccoons
Cutaneous larval migrans is caused by _________.
What is the major mode of transmission of ancyclostoma in dogs?
How do humans get ancyclostoma?
eggs develop to L3 to be infectious
What is a feature of ancylostoma after infection?
encystment and slow larval leak to GI tract
How do you prevent ancyclostoma infection?
deworm, remove fresh feces
How do you prevent infection with trichinella?
deworm, cook meat
How is trichinella transmitted?
ingestion of undercooked meat
Trichinella has been transmitted through __________ in the USA.
ingestion of undercooked pork
Angiostrongylus is the _________.
rat lung worm
Angiostrongylus has a _______ intermediate host.
What are the consequences of aberrant host infection with Angiostrongylus?
How do you prevent infection with Angiostrongylus?
don't eat raw snails, raw shrimp, or greens contaminated with them
Describe the disease caused by Giardia in animals and humans. (4)
diarrhea, greasy stool, gas, vomiting
What is similar b/w asymptomatic and symptomatic dogs with Giardia?
both have Giardia and BOTH SHED PARASITE
How do you collect samples to test for Giardia?
collect stool samples several days in a row due to intermittent shedding
What are the stages of Giardia?
cyst and trophozoite
What stage of Giardia is resistant?
cysts (but they are susceptible to desiccation and direct sunlight)
How do you prevent infection with Giardia?
avoid ingestion of untreated water, practice good hygiene
What is the direct host of Toxoplasma?
What is the intermediate host of Toxoplasma?
Previous exposure to Toxoplasma means...
resistent to new infections (IgG seropositive), reactivation during immunosuppressive events
Why is Toxoplasma recrudescent during immunosuppressive events?
latent tissue cyst remains dormant due to normal immune system; loss of normal immune system allows it to replicate and cause CNS disease
When is Toxoplasma most dangerous to pregnant women?
primary infection while pregnant (test cat to see if IgM or IgG seropositive or negative, make husband clean litter box, pick feces every day)
What is a possible consequence of primary infection with Toxoplasma during pregnancy?
: ocular disease
: learning problems, CNS disease, disabilities
What stage of Toxoplasma is shed in the feces? What is the significance of this?
unsporulated- not infective for ~24hrs (clean litter box every day!)
What disease does Toxoplasma cause in cats (DH)?
What coccidia are immediately infective when shed in the feces?
What are the modes of transmission of Toxoplasma?
sporulated oocysts (cat poo), undercooked meat with tissue cysts, ingestion of contaminated vegetables (cat pooped in your garden)
How many crypto organisms are required to initiate infection?
What are host species for crypto?
What are the modes of transmission of crypto?
feco-oral of sporulated oocyte, auto-infection by rupture of thin-walled oocytes
Describe the disease caused by crypto in animals. (3)
anorexia, watery diarrhea, tenesmus
What is the incubation period for crypto infection in humans?
1-12 days, generally self-limiting
Crypto can be lethal in ___________.
How do you prevent and treat infection with crypto?
hygiene, supportive treatment
What is the DH of cestodes?
What stage of Echinococcus is infective to humans?
Echinococcus granulosus has a _________ larval cestode stage.
unilocular hyatid cyst
Echinococcus multilocularis has a _________ larval cestode stage.
multilocular hyatid cyst (buds off)
What stage of cestodes is infective?
Why is there not an enormous immune response against hyatid cysts of Echinococcus?
it has a fibrous capsule that walls it off
What is the cause of pathology associated with hyatid cysts of Echinococcus?
travels to liver, space occupying lesion
What are the modes of transmission of Echinococcus granulosus?
eggs in feces, alveolar cyst
What are the modes of transmission of Echinococcus multilocularis?
eggs in feces, exogenous cysts
How do you prevent infection with Echinococcus?
can't see in feces- hygiene, deworm
What is the difference between Echinococcus and Taenia grossly?
can't see Echinococcus (microscopic), can see taenia
The cysticerci of Taenia solium have a trophism for _________.
Humans are a ______ of Taenia solium.
DH or IH
What is the IH of Taenia sainata?
Describe disease caused by Taenia solium in humans.
taeniosis (GI discomfort), CNS- seizures, epilepsy, headaches, blindness, death
DH of Diplydium caninum.
IH of Diplydium caninum.