Trematodes Flashcards
Lizard fluke
Platynosomum fastosum (P. Concinnum)
Lung fluke
Paragominus kellicotti
Salmon poison fluke and associated disease causing pathogen
Nanophyetus salmincola And neoriketsia helminoika
Canine blood fluke
Heterobilharzia americana
Snail to tadpole to lungs and mammary tissue name
Alaris spp.
ID trematodes and egg
flat/UNSEGMENTED
Ventral acetabulum
2 blind ceca
hermaphrodites (except shistosome)
opercalated egg (except shistosome)
Trematodes life cycle
Indirect (most 2 IH with 1st being snail)
miracidium released from opercalated egg in ENV –> infect snail become sporocyst–> redia –> circaria which either
pentrates the DH directly (no metacercaria) or
ingested/penetrate 2nd IH or encysted on vegetation –> metacercaria (infective stage when ingested by DH)
infective stage of 1st IH (snail)
miracidium (penetrates)
infective stage of 2nd IH
cercaria
either:
ingested/penetrate 2nd IH and encyst
encyst on vegetation
(penetration of DH)
Flukes true infective stage (of DH)
metacercaria
via ingestion of encysted vegetation or 2nd IH
Platynosomum fastosum IH and DH
1 IH: TERESTRIAL SNAIL
2 IH: Anolis lizard
DH: Cat (BILE DUCT)
Treatment of Trematodes
Praziquantel / Fenbendazone (high doses)
(non approved)
Paragonimus kellicotti IH and DH
1 IH: freshwater snail
2 IH: crayfish
DH: dog/cat/mink LUNGS
Pathogenesis of Paragonimus kellicotti (larval migrans and adult)
migration: esoinophilic peritonitis, pleural hemmorage
Adult: chronic bronchitis, granulomatous pnemonia, ect.
Nanophyetus salmincola IH and DH
1 IH: AQUATIC snail
2 IH: fish (trout/salmon) kindey/Muscle/fin
DH:pescitarians (dog cat mammals) HUMANS* SI CRYPTS
Nanophyetus salmincola pathogenesis
adults often minimal +/- enteritis
** BUT carriers of Neorickettsia helminthoeca (protazoa) = salmon poisoning
= fever anorexia v+ d+ (90% mortaltity 2w w/o tx)
Best diagnostics for trematodes
Fecal sedimetnation
differences of the shistosomes (heterobilharzia americana) vs other trematodes
(sex-ID/egg/ gross/ location)
True male and femal (dioeceious)
male with gynecophoric canal to carry female
NON OPERCULATED EGG - lateral/termnal spine
inhabit blood vessles
grossly appear round like nematodes
Diagnosing heterobilharzia americana
sediment with 0.9% saline (instead of water)
+/- float
PCR tissues / Histo
Heterobilharzia americana IH and DH
1 IH: freshwater snail
DH: RACOON, dog bobcat horse MESENTERIC HEPATIC VEIN
trematodes with zoonotic potential
nanophyetus salmincola (DH) in SI crytps
Heterobilharzia americana (DH) -penetration by cercaria hepatic/mesenteric veins
infection of DH (racoon, dog, bobcat, human) by Heterobilharzia americana
DIRECT penetation of CERCARIA (no intermediate host!*)
pathogenesis of Heterobilharzia americana
usually asymptomatic but
larvae: +/- cercarial dermatitis at site of penetration = skin rash with pustular eruptions (swimmmers itch)
eggs in tissue/to SI lumen: granulomatous infalmation, calcification
Alaria spp. IH and DH
(+ life cycle)
1 IH: freshwater snail (miracidium)
2 IH: tadpole
(Paratenic H: frog snake bird)
DH: dog/cat
male/female: ingest 2 IH/PH MESOCERCARIAE penetrate diaphragm –> lungs METACERCARIAE up trachea swallowed self infect
vs lactating cat MESOCERCARIAE migrate mammary glands shed in milk –> adults in kittens (some mesocercaria remain will infect future litters)
What larval stage migrates to mamarry tissue in lactating queens
mesocercaria
(mature to adults in kitten)
pathogenesis of Alaris spp.
adults usually non pathogenic
migrating juvenile: pulmonary hemmorage
