Trematodes pt 2 Flashcards
Paragonimus kellicotti
- DH: dogs, cats, muskrats, mink, wild/domestic carnivores, humans
- 1st IH: aquatic snails
- 2nd IH: crayfish
- PH: rodents
- DH adults in lung parenchyma (encysted)
Paragonimus kellicotti prevalence
North America (bobcats) - Paragonimus spp: Asia, Americas, Africa
Paragonimus kellicotti life cycle
DH ingests crayfish with mature metacercariae or PH (ingested crayfish w/ metacercariae) –> excyst in SI, penetrates gut to peritoneal cavity to diaphragm to lungs –> form cysts in lung parenchyma, mature to adults –> eggs pass from cyst to bronchi –> eggs coughed up and swallowed –> unembryonated eggs in feces –> miracidia hatch, penetrate aquatic snail –> cercariae emerge, enter crayfish –> metacercariae form, infections in 42-46 days
Paragonimus kellicotti pathology
Asymptomatic
- migrating flukes: eosinophilic peritonitis, pleuritis, multifocal pleural hemorrhage
- chronic bronchiolitis
- bronchiole epithelial hyperplasia
- ruptured cysts (acute pneumothorax)
- degenerating eggs: chronic eosinophilic granulomatous pneumonia
Paragonimus kellicotti clinical signs
- deep coughing
- dyspnea
- hemoptysis
- lethargy
- weakness
- weight loss
Paragonimus kellicotti diagnosis
Eggs - thick shelled, yellow - operculum - fecal sedimentation or flotation - lung: fluid wash Adult - radiograph for pulmonary cysts - necropsy
Paragonimus kellicotti treatment/control
- fenbendazole
- albendazole
- praziquantel
- prevent ingestion of IH and PH
Paragonimus kellicotti human infection
Rare in US
- ingestion of raw/undercooked crayfish
- diarrhea, abdominal pain, chest pain, thick sputum production, similar to TB!
- praziquantel
- Paragonimus westermani: oriental lung fluke
Nanophyetus salmincola
- DH: raccoon, mink, fox, coyote, dog, cat, piscivorous birds/mammals
- 1st IH: aquatic snails
- 2nd IH: fish, pacific giant salamanders
- DH site: SI
- 2nd IH site: kidneys, muscle, fins, other organs
Nanophyetus salmincola prevalence
North America
- pacific northwest US
Nanophyetus salmincola life cycle
DH ingests fish with metacerariae –> develop to adults in SI, NO extra intestinal migration! –> unembryonated eggs passed in feces –> miracidia catch, infect aquatic snail –> cercariae emerge from snail –> cercariae penetrate young fish (salmonids) –> metacercariae form in kidneys, muscle, fins
Nanophyetus salmincola pathology - fish IH
Metacercariae
- renal edema
- hemorrhagic skin
- obstruction to heart, retina, kidney tubules, pancreatic tissue, gallbladder
- exophthalmia
- decreased or erratic swimming
Nanophyetus salmincola pathology - canine DH
Adult trematodes
- hemorrhagic enteritis
- rarely disease
Neorickettsia helminthoeca
Salmon poisoning disease
- transovarial transmission in trematode
- trematode adheres to intestine (rickettsiae enter epithelial cells)
Salmon poisoning in dogs
Sudden fever, persistent vomiting, bloody diarrhea, ocular discharge, etc
- mortality: 50-90%
- diagnosis: lymph node aspiration, trematode eggs in feces
- treatment: tetracycline, doxycycline, supportive therapy for dehydration
Nanophyetus salmincola diagnosis
Eggs - fecal sedimentation/flotation - yellow to brown - indistinct operculum Adults - oral and ventral sucker - spiny tegument - pair of large oval testes
Nanophyetus salmincola treatment/control
- praziquantel
- no feeding raw or undercooked fish
Nanophyetus human infections
Rare, fish flu
- eating undercooked fish
- diarrhea, abdominal pain
- prazi, niclosamide
Alaria
- DH: dog, cat, wide range of carnivores
- 1st IH: aquatic snails
- 2nd IH: tadpoles
- PH: frog, snake, mice, mammals
- site in DH: SI or mammary glands in lactating cats
Alaria life cycle
DH ingests infected tadpole or PH with mesocercariae –> migration to diaphragm to lungs, develop into metacercariae, coughed up trachea down esophagus to SI or in lactating cat, mesocercariae migrate to mammary glands –> develop to adults in SI or remain mesocercariae (transmammary) –> unembryonated eggs in feces –> miracidia hatch, infect aquatic snail –> cercariae emerge in water —> cercariae penetrate tadpole, develop into mesocercariae –> PH ingests tadpole with mesocercariae
Alaria transmammary transmission in the ______
Lactating cat
- mesocercariae migrate to mammary glands
- dormant tissue stages (remain mesocercariae, passed during lactation)
- develop into adults in kittens
Alaria pathology
Cat DH - attached to mucous membranes of SI - migratory tracts thru lung parenchyma - usually little harm IH and DH - migration
Alaria diagnosis
Eggs - fecal sedimentation - operculum Adults - winged, 2 tentacle like structures along oral sucker Mesocercariae - dormancy
Alaria treatment/control
- praziquantel
- prevent ingestion of tadpoles or PH
Alaria human infection
A. americana
- fatal, extensive pulmonary hemorrhage
- subq nodules
- pulmonary nodules
- several cases of intra-ocular mesocercariae leading to blindness
Potomac horse fever
Equine neorickettsiosis
- digenetic trematodes serve as reservoir (Acanthatrium oregonense)
- infectious agent (Neorickettsia risticii)
- > 25 states and canada
Acanthatrium oregonense life cycle
DH (bat) ingests insect with metacercariae –> bat with adult trematode –> eggs shed in feces into water –> miracidia hatch, infect aquatic snail –> cercariae emerge in water, infect aquatic insects –> metacerariae develop inside insect –> aberrant equine host ingests mayfly with metacerariae harboring Neorickettsia risticii
Potomac horse fever clinical signs
10-18 days post infection
- depression, anorexia, fever
- diarrhea, mild colic
- laminitis
- abortion
- mortality without treatment
Potomac horse fever diagnosis
- clinical signs
- isolation of N. risticii (blood and feces)
- ab titers
Potomac horse fever treatment
Oxytetracycline
Potomac horse fever control
Prevent ingestion of insects (difficult)
Heterobilharzia americana
- DH: raccoons, dogs, bobcats, nutria, opossum, panther, beaver
- IH: lymnaeid snails
- DH site: hepatic portal and mesenteric veins
- canine schistosomiasis
Heterobilharzia americana prevalence
Southeastern US
Heterobilharzia americana life cycle
Miracidia hatch in water, infect a lymnaeid snail –> cercariae emerge and penetrate the skin of DH –> migration thru lungs to liver –> mature to adults –> adults migrate thru portal veins to mesenteric veins –> eggs migrate thru mesenteric veins and intestinal wall to lumen of intestine –> embryonated eggs shed in feces
Heterobilharzia americana requires a _____ solution for sedimentation
Saline, so eggs do not hatch
Heterobilharzia ameriana pathology
Canine DH
- severe granulomatous inflammation: SI, liver, LI, pancreas
- fibrosis
- mineralization
- death
Heterobilharzia americana clinical signs
- diarrhea (bloody)
- weight loss
- anorexia
- vomiting
- lethargy
- blood chemistry usually normal (hypercalcemia)
Heterobilharzia americana diagnosis
Eggs - thin shelled, no spine - fecal sedimentation (saline) - fecal PCR - biopsy Adults - mesenteric veins - dioecious
Heterobilharzia americana treatment/control
- fenbendazole, praziquantel
- prevent exposure to cercariae
Heterobilharzia americana human infections
Swimmers itch
- cercarial dermatitis: edema, itching, papules
- avian schistosomes
- avoid water where cercariae infected snails are present
