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Parasitology
Nematodes cont for CBT 2
150
Veterinary Medicine
Undergraduate 3
04/12/2009

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Term
LC type of ascaridoids
Definition
indirect - based on predator prey relationship
Term
What organ do ascaridoids mature in?
Definition
mostly in SI
Term
Ascaridoid typical mouth structure
Definition
3 lips
Term
What stage is in the ascaridoid egg
Definition
L3
Term
what is the infective stage for ascaridoid DH/IH/PH
Definition
L3 in egg ??
Term
is there a free living stage in the ascaridoid LC
Definition
no
Term
Family Ascarididae contains
Definition
spp of veterinary importance - T.canis, T.catis, P.equorum, A.suum
Term
Host of Ascaris suum
Definition
pig
Term
LC type of Ascaris suum
Definition
direct (abnorm)
Term
how is pig infected by Ascaris suum
Definition
pig ingests L3 in the egg OR earthworms that have ingested the infective eggs = PH
Term
What about Ascaris suum eggs makes them resistant
Definition
they are thick shelled with outer proteinaceous coat
Term
Ascarid suum eggs - triggered hatching in what organ in response to what
Definition
SI in response to dissolved CO2, neutral pH, presence of reducing substances and at body temp
Term
Migration route of Ascaris suum
Definition
L3 enter blood stream - liver - lungs (moult) trachea - alimentary tract, w L4 maturing in SI intestine (hepatic-pulmonary)
Term
PPP of Ascarus suum
Definition
8 weeks
Term
Is Ascaris suum migratory?
Definition
yes
Term
Clinical significance of Ascaris suum
Definition
Large nematodes obstruct the intestine, severe liver damage can also result
Term
Ascaris suum and aquired resistance
Definition
good aquired resistance developes - therefore very young piglets are very easily infected w large numbers of worms. adults may carry small numbers
Term
Ascari lumbricoides
Definition
commn parasite of man - not easily distinguishable from A.suum ,but not transmissible b/t man and pig.
Term
Visceral larva migrans
Definition
Conditions for hatching of Ascaridoid eggs are similar in most mammal SI - eggs hatch and migrate to liver and lungs, but do not norm mature. (larvae are much less host specific than the adults) Ability to infect a wide variety of hosts = utilise IH/PH
Term
Organ of Parascaris equorum
Definition
SI
Term
host of Parascaris equorum
Definition
equidae
Term
PPP of Parascaris equorum
Definition
10-12 weeks
Term
entry into DH by Parascaris equorum by
Definition
ingestion of L3 in egg
Term
migration type of Parascaris equorum
Definition
hepatic-tracheal
Term
Significance of Parascaris equorum
Definition
Large nematodes cause obstruction of the intestine (SI impactions), can cause severe liver damage too
Term
Genus Toxocara contains
Definition
T.canis, T.cati
Term
Genus Parascaris contains
Definition
Parascaris equorum
Term
host of Toxocara canis
Definition
dogs and other canids only
Term
Infection by Toxocara canis is by one of 4 ways:
Definition
1. L3 ingested in egg
2. L3 in paratenic host ingested (poss, but unlikely)
3. Transmammary infection (uncomm and unimport)
4. Prenatal infection v import as virtually 100% of pups are born infected
Term
Explain prenatal infection of Toxocara canis
Definition
Larvae that are encysted in the tissues of the bitch are mobilised during preg, passing in the blood across the placenta to the fetal blood stream - fetal liver.
When pups are born - larvae migrate to the lungs - intestine.
Min PPP 23dd
Most import source of patent Toxocara infections
Term
Does the bitch have to be re-infected b/t each litter to produce infected pups
Definition
No, only some of the larvae are mobilised w each preg, but the bitch is norm reinfected from the patent infections produced in the pups. Therefore she acts as a PH
Term
Name a PH in Toxocara canis infection involving newborn pups
Definition
bitch herself
Term
Most import cause of visceral larva migrans in man
Definition
Toxocara canis - esp in young children who ingest infective eggs
Term
Explain L3 ingestion in egg of Toxocara canis by 5-10week old pups
Definition
hepatic-tracheal migratio, patent infection produced.
Min PPP 4-5 weeks
Term
Explain L3 ingestion in egg of Toxocara canis by older dogs
Definition
most larvae pass thru the lungs and are distributed to somatic tissues where they remain encysted and alive (as L3) Patent infections are more difficult to produce
Term
Are ascaridoid eggs immediately infective?
Definition
No - egg is laid with a zygote-morula-L1-L2-L3=infective. There is no further dvt until ingested - triggered hatching
Term
Ascaridoid migration type
Definition
Hepatic tracheal migration
Term
"milk spot"
Definition
A's of scarring in pig liver left behind after migration of Ascaris suum
Term
What do ascarids feed on?
Definition
Digesta - v big nematodes in the lumen of SI, too big for diffusion
Term
Migration of non-patent ascaridoids (esp import in Toxocara spp)
Definition
somatic migration - liver to lungs to somatic tissues
Term
PPP of Toxocara canis
Definition
Varies with route of infection
-newborns = 23 dd
-5-10 week old pups = 4-5 weeks
Term
Host of Toxocara cati
Definition
cats and felids only
Term
Three modes of infection of Toxocara cati
Definition
1. ingestion of L3 in egg
2. Transmammary infection
3. Ingestion of L3 in egg by PH - hatches migrates in tissues - encysts as L3 - ingestion of PH by DH (no migration in DH)
Term
PPP of Toxocara cati
Definition
depends on route of infection:
1. ingestion of L3 in egg - 56 dd
2. Transmammary - 47 dd
Term
Migration type of Toxocara cati after ingestion of L3 in egg
Definition
hepatic-tracheal
Term
Patent infection of Toxocara cati
Definition
often more successful in older cats - older cats can shed eggs
Term
Vomition due to Ascaridoids in dogs and cats
Definition
vomition is stimulated by migration of worms in the stomach - pneumonia may result from inhalation of the vomit or migration of the larvae.
Term
Significance of Ascaridoids in dogs and cats
Definition
-vomiting
-pneumonia
-intestinal symptoms = diarrhoea, vomiting, unthriftiness, pot belly due to partial or complete obstruction of the intesting by the large nematodes
Term
Host of Ascaridia galli
Definition
chicken and other birds
Term
Organ of Ascaridia galli
Definition
SI
Term
LC of Ascaridia galli
Definition
simple and direct
Term
Infection of Ascaridia galli
Definition
ingestion of L3 in the egg
Term
Transport host of Ascaridia galli
Definition
earthworm
Term
migration of Ascaridia galli
Definition
there is no migration
Term
Significance of Ascaridia galli
Definition
Can interfere with poultry growth and egg production by interfering with absorption and competing with host for Vitamin A
Term
Organ of Heterakidae gallinarum
Definition
caca
Term
Host of Heterakis gallinarium
Definition
poultry
Term
Significance of Heterakis gallinarium
Definition
v common, but not pathogenic. Transmits the protozoal parasite Histomonas meleagridis
Term
Histomonas meleagridis
Definition
Protozoal parasite that causes infectious enterohepatitis in turkeys and chickens. Transmitted by Heterakis gallinarium
Term
"blackhead"
Definition
Infectious enterohepatitis
Term
Are ascaridoid nematodes prolific?
Definition
yes
Term
Toxocara cati can infect DH or IH
Definition
This means that indeirect LC is optional
Term
Migration and immune resistance
Definition
most ascaridoid nematodes mgrate in the DH and so stimulate a good acquired resistance
Term
Ascaridoid strategies for continuation in herbivore spp
Definition
1.Outer proteinaceous coat:
-stickiness of the egg makes eggs stick to things eg. udder
-resistant therefore lasts in the env for a long time
2.Production of large numbers of eggs
Term
Significance of Ascaridoid nematodes
Definition
they cause SI impactions, compete with host for nutrients (have high MR - producing large numbers of eggs) cause liver and lung damage
Term
To prevent infections in pups becoming patent when should you treat with anthelmintics
Definition
2, 3 and 4 weeks after birth
Term
Pinworm Superfamily
Definition
Oxyuroidea (order - Oxyurida)
Term
Organ of Oxyuroidea
Definition
colon and rectum (distal LI)
Term
LC type of Oxyurida
Definition
direct
Term
What do Oxyurids feed on
Definition
gut contents, they exert their pathogenic effects by other means
Term
host of Oxyuris equi
Definition
equidae
Term
Describe the method by which Oxyuris equi lays eggs
Definition
Female partly emerges from the horses anus, anchored by her long tail. The eggs, which are sticky (and layed in a foamy white proetinaceous secretion) are smeared around the anus and perineal area
Term
infective stage of Oxyuris equi
Definition
L2 in egg - eggs may drop off the animal and infection is by ingestion of egg
Term
Migration of Oxyuris equi
Definition
there is no migration, they dvp in intestine
Term
Clinical signs of Oxyuris equi
Definition
tail rubbing of horses due to irritation caused by activity of females laying eggs
Term
Family of Probstmayria vivipara
Definition
Oxyuridae
Term
Host of Probstmayria vivipara
Definition
horses
Term
Organ of Probstmayria vivipara
Definition
colon
Term
Infectivity of Probstmayria vivipara
Definition
they are larviparous and autoinfectious therefore can dvp v larg infections but aren't pathogenic
Term
Family of Enterobius vermicularis
Definition
Oxyuridae
Term
host of Enterobius vermicularis
Definition
man - v common.
Term
LC of Enterobius vermicularis
Definition
L2 in egg infectious, ingestion, no migration. perineal irritaion causes scratching of anal region, transfer of eggs to mouth
Term
Whipworms
Definition
Trichuris genus - anterior end is narrower than posterior
Term
LC type of trichuris
Definition
direct
Term
infective stage of Trichuris
Definition
L1 in egg
Term
Route of infection of Tichuris
Definition
ingestion - infective stage is L1 in egg
Term
migration of Trichuris
Definition
eggs hatch in intestine w no migration
Term
Pathogenesis of Trichuris
Definition
narrow anterior end burrows into intestinal mucosa in shallow horizontal tunnels producing severe inflam
Term
Trichuris ovis host
Definition
sheep/goats
Term
sp of Trichuris in sheep and goats
Definition
Trichuris ovis
Term
Sp of Trichuris in pigs
Definition
Trichuris suis
Term
sp of Trichuris in dogs
Definition
Trichuris vulpis
Term
sp of Trichuris in cats
Definition
cats don't have a sp of Trichuris
Term
Clinical signs of Trichuris infection
Definition
diarrhoea and loss of condition due to inflam in the caecum and colon. pathogenic effects are related to the numbers of parasites present
Term
Genus Capillaria is in which family
Definition
Trichuridae (same family as Trichuris)
Term
LC type of Capillaria
Definition
direct - L1 in egg infective
or indirect - L1 in earthworm is IH (L1 is still the infective stage)
Term
Capillaria spp are most import in what type of animals
Definition
birds - they are the most import helminths of chickens in NZ
Term
Host/organ/LC of Capillaria contorta
Definition
Poultry, esophagus and crop, indirect
Term
Capillaria spp in crop and oesophagus of poultry
Definition
Capillaria contorta
Term
Capillaria caudinflata organ and LC
Definition
SI and indirect
Term
Capillaria obsingnata organ and LC
Definition
SI and direct
Term
Capillaria in Rt's
Definition
c.bovis, C.longipes, C.brevipes all occur in NZ, have direct LC's and inhabit SI. Small numbers only, not of significance
Term
Capillaria erinacei
Definition
norm a parasite of hedgehogs, sometimes found in stom of cats and dogs. Direct LC
Term
Capillaria aerophilia
Definition
trachea and bronchi of cats and dogs. Direct LC
Term
Trichinella spiralis route of infection
Definition
infestion of larvae in muscle therefore largely confined to carnivores and scavengers
Term
Where do adults of Trichinella spiralis live
Definition
in SI, but they don't live long after completing dvt
Term
What and where do female Trichinella spiralis nematodes give birth to
Definition
After copulation they burrow into mucosa and give birth to L1. They are larviparous
Term
Once L1 Trichinella spiralis have been laid what do they do
Definition
They enter villi lymphatics - bloodstream - voluntary mm - enter mm fibre using buccal lancet - dvp and grow (causing fibre to degenerate) and sarcolemma forms a cyst wall. Some of surrounding mm fibres may degenerate - fibrous tissue. Larvae appears to be in a fibrous cyst.
Term
How long does a Trichinella spiralis L1 cyst remain viable for
Definition
Many years - may outlive the host. May b/c calcified.
Term
When is the Trichinella spiralis cyst completely formed by
Definition
3 months after infection
Term
What releases Trichinella spiralis L1 from cysts after ingestion
Definition
They are released in the intest by digestion of the cyst wall. Worms b/c sexually mature in 3-4 days
Term
How long after release from the cyst does it take for Trichinella spiralis L1 to b/c sexually mature
Definition
3-4 days
Term
How are Trichinella spiralis L1 passed out in faeces
Definition
Some infective L1 are released in the intestine after ingestion by the host (once they are released from the cysts)
Term
Significance of Trichinella spiralis
Definition
import lies in it's transmissibility to man - ingestion of raw/inadequately cooked meat
Term
Host specificity of Trichinella spiralis
Definition
will dvp and reproduce in any mammal. but main hosts are pigs, rats and cats
Term
Infection of Trichinella spiralis
Definition
Trichinosis
Term
What is the most import source of infection of Trichinella spiralis for pigs
Definition
Feeding of uncooked household waste, next most import is rat contaminated pig food (~)
Term
Order: Spirurida LC
Definition
Involve arthropod or crustacean IH
Term
Where are Spirurids more import
Definition
Tropical climates
Term
Where are Spirurids found
Definition
Upper alimentary tract mam's and birds
Term
LC type of Spirurids
Definition
Always indirect thru crustacean/arthropod
Term
Infective stage of Spirurids
Definition
L3
Term
Migration of Spirurids
Definition
no migration
Term
Spirurid genera found in the stom of horses
Definition
Habronema, Draschia
Term
Location of Habronema/Draschia
Definition
lumen or in nodules in the stom wall
Term
LC of Habronema/Draschia
Definition
Eggs (w L1) passed in faeces - fly larvae ingest eggs in faeces - dvp to L3 in maggot - L3 breaks out of probiscus of adult fly in response to moisture (wounds, horse breath- if near breathe will be ingested etc) - larva dvps without migration
Term
Cutaneous habronemiasis
Definition
L3 Habronema are deposited on wounds where flies feed, cause severe inflam response = cutaneous habronemiasis
Term
IH of Habronema/Draschia
Definition
Muscoidflies eg. Musca domestica (common house fly)
Term
Filaroidea are parasites of where/what
Definition
blood, lymph and CT
Term
IH of Filaroidea
Definition
usually blood/lymph sucking flies (seeing as the worms live in lymph/blood/CT)
Term
How is IH of Filaroidea infected
Definition
By ingesting the microfilariae in host fluids while feeding
Term
L1 of Filaroidea
Definition
Microfilaria
Term
LC of Filaroidea
Definition
IH ingests microfilariae as it feeds - dvps to L3 (infective for DH) - is injected into DH when vector feeds
Term
PPP of Dirofilaria immitis
Definition
6-7 months
Term
Organ of Dirofilaria immitis
Definition
pulmonary a and right ventricle of dog
Term
What do female Dirofilaria immitis give birth to
Definition
they are larviparous - microfilaria
Term
When are microfilaria more numerous in the blood
Definition
morning and night - when mosquitos feed (periodicity)
Term
IH of Dirofilaria immitis
Definition
mosquitos
Term
How long does it take for microfilaria to dvp to L3 in mosquito
Definition
2-3 weeks
Term
Significance of Dirofilaria immitis
Definition
Infection interferes with blood flow through pulmonary artery - heart failure
Term
How does L3 Dirofilaria immitis infect dog
Definition
Infective stages are found in salivary glands of mosquito - injected w saliva when they feed
Term
Name Filaroid nematode endemic in NZ dogs
Definition
Dipetalonema reconditum
Term
Organ of Dipetalonema reconditum
Definition
SC and intermm CT of dogs
Term
IH of Dipetalonema reconditum
Definition
Fleas
Term
How can infection of Dipetalonema reconditum be distinguished from Dirofilaria immitis
Definition
Size of microfiliaria in blood (immitis>reconditum)
Term
Significance of Dipetalonema reconditum
Definition
It is non-pathogenic, but it does need to be distinguished from Dirofilaria immitis
Term
Significance of Dipetalonema reconditum
Definition
It is non-pathogenic, but it does need to be distinguished from Dirofilaria immitis
Term
Parasitemia
Definition
periods of high levels of microfilariae in the blood that coincides with periods of high feeding activity of IH
Term
How is DH of Dirofilaria and Dipetalonema reconditum infected
Definition
infective stage (L3) is in saliva of IH an is injected when the IH feeds
Term
Nematode that causes elephantitis
Definition
Wuchereria bancrofti - causes lymph stasis
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