Parasitology 5: Ascaridida Flashcards
Main characteristics Ascaridida nematoda
Big
Robust
GI tract
Lay term name for Ascaridida
Roundworms
Significance of size for Ascaridida
- Biggest nematodes
- Between 5 - 40 cm
Type life cycle for Ascaridida
Direct
Where do Ascaridida live and what do they feed on?
- Live in lumen (unattached)
- Feed on lumen contents, host fluids
Characteristics of Ascaridida egss
LIVE UP TO 10 YEARS
- Unembryonated
- Thick shell
- High resistant to environmental conditions
When is Ascaridida infective stage?
(Egg with L3)
- Embryonated egg
- The infective larva will not hatch until egg is swallowed by the host.
How to diagnose Ascaridida?
- Eggs in feces
- patent infections are easy to diagnose
What is this, what is specific about it?
Ascaridida egg
- thick, rough shelled
Ascaridida mammalliam species?
Parascaris spp.
Toxocara spp.
Parascaris spp Ascaridida infects what animal?
Horses
Lifecycle of Parascaris?
- Eggs passed in manure
- Larvae hatch in intestine, penetrate lumen wall
- Hepatotracheal migration: Carried to liver in blood - Enter hepatic portal system - Reach lungs 1 wk after infection - Coughed up and swallowed - Return to small intestine
- Prepatent period ~3 months
Parascaris clinical important?
- Young horses
- Low worm numbers can be subclinical
- Adults in small intestine
- Larvae in lungs
What is the clinical significance of parascaris adults in small intestine?
- Compete with host for nutrients
- Poor condition
- Rough hair coat
- Pot bell
- Very heavy infection can lead to obstruction or perforation of impaction of GIT
What is the clinical significance of parascaris Ascaridida in the lungs?
- Mechanical and inflammatory damage
- Nasal discharge
What is the immunity trends of parascaris?
- Immunity develops well so adults rarely have patent infections
- Adults do not ply a role in parasite transmission
- Occurs in young horses (<2-3 years)
What breed is Toxocara canis and cati in?
Dogs and cat
Special characteristics of toxocara cati?
Narrow head with wing shaped.
Pathognomic of this nematode.
Toxacara canis survival in environment?
- Eggs passed in feces
- takes 3-4 weeks in the environment to become infective
- can survive in environment fo r2-3 years
life cycle of toxocara canis
Routes of transmission for Toxocara canis?
- Ingestion of infective eggs
- Transplacental**
- Transmammary infection
- Paratenic hosts
Toxocara canis clin signs in severe cases
- Diarrhea
- Colic
- pot belly
- Vomiting (worms can be seen)
- Poor hair coat
- Intestinal obstruction
- pneumonia
How to diagnose Toxocara caninia?
- Patent infectionsL fecal exam
- Somatic survivors
What are the big 3 nematodes?
Hookworms
Roundworms
Whipworms
Toxocara cati significance?
- Somatic reservoir is less important than canis
- Some transmammary seems to be less important
- longer PPP
Swine Ascaridida?
- Zootonitc
- Ascaris suum
Racoon Ascaridida?
- Zoonotic
- Baylisascaris procyonis
Humans Ascaridida?
Ascaris lumbricoides
Cattle Ascaridida?
Toxocara vitulorum
