Parasitology - Rhabiditida

Front 1

what is unique to the order Rhabditida?

Back 1

sexually reproducing free-living stage

Front 2

In genus Strongyloides describe the parasites?

Back 2

adults are small, only adult females are found in the small intestine of the host, have long filariform esophagus

Front 3

What is a distinguishing feature of free living adult Strongyloides?

Back 3

rhabditiform esophagus

Front 4

what is the host for Strongyloides stercoralis?

Back 4

Dogs, Cats, people

Front 5

what is the host for Strongyloides papillosus?

Back 5

Ruminants

Front 6

what is the host for Strongyloides weseteri?

Back 6

Equine

Front 7

what is the host for Strongyloides ransomi?

Back 7

Swine

Front 8

what is the morphology of Strongyloides stercoralis?

Back 8

adult female is parasitic (males are not); parthenogenic & sexual repro with L1, which hatches quickly, in feces

Front 9

what is the morphology of Strongyloides papillosus?

Back 9

larvated ova in feces

Front 10

what is the morphology of Strongyloides weseteri?

Back 10

larvated ova in feces

Front 11

what is the morphology of Strongyloides ransomi?

Back 11

larvated ova in feces

Front 12

what are the lifecycles of Strongyloides?

Back 12

homogonic or hetergonic

Front 13

describe the homogonic lifecyle of strongyloides?

Back 13

parthenogenic, 1 adult = 1 offspring; Parasitic female in SI [FE]à ova hatches in SI, L1 shed in feces (stercoralis) OR ova shed in feces (other) à L1-L2 free-living [RE] à L3 infective [FE] à transmission by skin/oral mucosa penetration à tissue migration to trachea/lungs (some somatic migration) à cough up L3 + reingest à maturation to parasitic female in SI [FE]

Front 14

describe the heterogonic lifecycle of strongyloides?

Back 14

sexual repro, increase in #offspring; Parasitic female in SI [FE]à ova hatches in SI, L1 shed in feces (stercoralis) or ova shed in feces (other) à L1-L4 free-living [RE] à adult free-living male + female [RE] à ova, L1-L2 free-living [RE]à L3 infective [FE] à skin/oral mucosa penetration à tissue migration to trachea/lungs (plus some somatic migration) à cough up L3 + reingest à maturation to parasitic female in SI

Front 15

during the homogonic cycle of Strongyloides how quickly can L1 progress to L3?

Back 15

within 24 hours

Front 16

during the homogonic cycle of Strongyloides what can autoinfection lead to?

Back 16

hyperinfection

Front 17

during the heterogonic cycle of Strongyloides where are increases in L3 found?

Back 17

environment

Front 18

What are the methods of transmission of Strongyloides?

Back 18

transmammary & autoinfection + hyperinfection

Front 19

what is another term for transmammary transmission?

Back 19

lactogenic route of infection

Front 20

how does transmammary transmission occur in Strongyloides?

Back 20

via arrested L3 in maternal tissues

Front 21

how does autoinfection + hyperinfection in humans/dogs?

Back 21

ova hatch in intestine & mature quickly, repenetrate GI wall (particularly in immunocompromised individuals with suppression of TH2 response)

Front 22

what are the pathological legions of Strongyloides?

Back 22

enteritis at location of parasitic adult females which are only 2-7mm long, petechial hemorhages in lungs where larvae migrated

Front 23

what are the clinical signs of Strongyloides?

Back 23

disease in very young (2w-2m) or naïve, congested lung sounds, diarrhea, larvated eggs (ruminants, horses, pigs) or rhabditiform L1 (dogs, cats, man) in fresh feces; fecal culture yields filariform larvae with 'notched' tail

Front 24

What is the source of environmental contamination with Strongyloides?

Back 24

young animals

Front 25

what is the source of infection of newborns with Strongyloides?

Back 25

lactating mothers

Front 26

what is the source of infection of mothers with Strongyloides?

Back 26

environmental contamination from young animals

Front 27

How do we prevent environment contamination of Strongyloides?

Back 27

treat newborns

Front 28

how do we treat Strongyloides in mares and foals?

Back 28

treat mares at foaling with ivermectin to reduce lactogenic infection in foals

Front 29

how can we stop the homogenic cycle in dog runs?

Back 29

clean twice a day

Front 30

what type of infection may occur between humans and dogs with Strongyloides?

Back 30

zoonotic; strain variability makes this unpredictable and requires regorous monitoring of infections (especially immunocompromised individuals)

Front 31

how may hyperinfection occur with Strongyloides?

Back 31

rapid L1 to L3 development in the gut of humans or dogs allows autoinfection