Parasites2 Flashcards
Toxocara canis
• “Roundworm” “Ascarid”
• Adult parasites are ~ 10-18 cm
• Eggs are round w/ a thick, pitted shell
-Fecal oral contact transfer.
-Prefers GI system.
-Can migrate to lungs, liver, fetus, or be transmitted by milk
Importance of Toxocara canis
-high percentage of pups infected, death in pups 2-3 wks old (lung damage), vomiting, diarrhea, visceral larva migrans-
Diagnosis and Control of Toxocara canis
- Diagnosis- Eggs in feces, worms in vomitus
* Control- Treat infected dogs, remove feces
Life cycle of Toxocara canis
- visceral migration occurs in pups < 3 mo.
- Old, tissue dormancy occurs in older dogs and mobilization to uterus is seen in the last trimester of pregnancy
Visceral Larva Migrans
• Damage to the body’s internal organs caused by a migrating roundworm larva • Causative parasites: o Toxocara canis o Toxocara cati o Baylisascaris procyonis
Syndrome of Visceral Larva Migrans
o Human– asymptomatic or mild signs
fever, cough, skin rash, abdominal pain, CNS abnormalities, ocular dz.
o Animal– malnourishment, vomiting, diarrhea
Incubation and Mortality of Visceral Larva Migrans
- Incubation period is weeks to months
* Mortality: Low
Occurrence and Transmission of Visceral Larva Migrans
- Occurrence - More of a problem in warm, moist climates
* Transmission- Ingestion of infective worm eggs
Diagnosis and Treatment of Visceral Larva Migrans
- Diagnosis- CBC, serology, ELISA test
* Treatment- Antiparasitics
Control and prevention of Visceral Larva Migrans
o Personal hygiene
o Regular deworming of dogs and cats
o Prevent contamination of soil w/ dog, cat feces
o Keep children from eating dirt or putting dirty objects in their mouth
Trichuris vulpis
• “Whipworm”
• Adult parasites are 4.5-7.5 cm long, thin anterior and thick posterior
• Eggs are barrel-shaped w/ transparent plugs ate each end
Worms are large on one end and taper down
• Adults live in LI (colon, cecum). Adults hide in cecum and only sporadically shed eggs
Very hard to diagnose and treat.
Diagnosis and Control of Trichuris vulpis
- Diagnosis- Eggs in feces, don’t typically see adults
* Control- Treat infected dogs, remove feces. Fecal-oral contamination.
Taenia pisiformis
• “Tapeworm” • Adult tapeworm is up to 200 cm long • Eggs passed w/in proglottids in the feces-NO cluster, no packet. YES hooklets- Small Intermediate host is rodent or rabbit Individual eggs
Importance and Diagnosis and Control of Taenia pisiformis
- Importance- diarrhea, intestinal obstruction, damage to intermediate host
- Diagnosis- Proglottids in feces/ perianal area
- Control- Prevent access to intermediate host, treat infected dogs
Hydatid Disease
- Disease caused by ingestion of tapeworm eggs
* Causative organism: Echinococcusgranulosus
Syndrome of Hydatid Disease
o Human– asymptomatic
o – presents like a slow growing tumor in an internal organ
o Animal– subclinical
Incubation and Mortality of Hydatid Disease
- Incubation period is months to years
* Mortality: 50-75%
Occurrence of Hydatid Disease
o Rural areas of northern hemisphere
o Sheep-raising areas of the SW U.S.
Diagnosis of Hydatid Disease
o Fecal flotation
o Recovery of tapeworm after administration of taeniafuge
Treatment of Hydatid Disease
Antiparasitics, surgical resection of cyst
Control and prevention of Hydatid Disease
o Regular deworming of dogs for tapeworms
o Prevent dogs from eating viscera of intermediate hosts
o Wash food potentially contaminated w/ dog feces
o Practice good personal hygiene
Taeniasis
• Tapeworm infection acquired from eating infected beef or pork
• Causative organisms:
o Taeniasaginata
o Taeniasolium
Syndrome of Taeniasis
Human– usually asymptomatic
o perianal irritation common
o – weight loss, abdominal pain, GI disturbances
o Cysticercosis- formation of cysts outside of the GI system
Animal– subclinical
Incubation and Mortality of Taeniasis
- Incubation period is 8 to 14 weeks
* Mortality: usually none, cysticercosis possibly fatal w/o treatment
Occurrence of Taeniasis
o Places where beef or pork is eaten raw or undercooked
o Places where pigs and cattle are permitted access to human feces
Transmission of Taeniasis
o Ingestion of cysticerci in raw or undercooked beef or pork
o Ingestion of Taeniasolium leading to cysticercosis in humans
Diagnosis and Treatment of Taeniasis
- Diagnosis- Proglottids in stool, fecal flotation, serology
* Treatment- Antiparasitics, surgical resection of cysticerci
Control and prevention of Taeniasis
o Prevent contamination of swine/cattle feed w/ human feces
o Cook meat well or freeze it (for at least 4 days) before eating
o Personal hygiene
o Don’t fertilize gardens w/ human waste
Diphyllobothriasis
- Tapeworm infection acquired by eating infected raw fish
- Causative organism: Diphyllobothrium spp.
- Incubation period is 3 to 6 weeks
Syndrome of Diphyllobothriasis
o Human– asymptomatic
– diarrhea, vomiting, anorexia, nausea, wt. loss, craving for salt, anemia, intestinal obstruction
o Animal– subclinical
Transmission, Diagnosis, Treatment of Diphyllobothriasis
- Transmission -Human consumption of infected raw or undercooked fish
- Diagnosis- Proglottids in stool, fecal flotation, CBC
- Treatment- Antiparasitics
Control and prevention of Diphyllobothriasis
o Cook fish well or freeze it before eating
o Prevent fecal contamination of water
Nanophyetussalmincola
“Salmon Poisoning Fluke”
• Adults are leaf-shaped organisms 0.5-1.5 mm
• Eggs are operculated, gold-colored
Neorickettsiahelmintheca
Importanc, Diagnosis, Control of Nanophyetussalmincola
- Importance- Vector for salmon poisoning disease bacteria
- Diagnosis- Eggs in feces, history, clinical signs
- Control- Prevent eating of wild fish, treat infected dogs
Fasciola hepatica
Fasciola hepatica
• “Liver Fluke”
• Adult is leaf-shaped 3-4 cm
• Eggs are operculated, yellow-green
Importance, Diagnosis, Control of Fasciola hepatica
- Importance- weight loss, liver disease, liver condemnation
- Diagnosis- Eggs in feces, antigen test
- Control- Fence-off snail infested bodies of water, treat infected animal
Isospora sp
- “Coccidia”
* Only oocyst observedà clear outer ring surrounding greyish center
Importance, Diagnosis, Control of Isospora sp
- Importance- diarrhea in puppies
- Diagnosis- Oocysts in feces
- Control- Treat infected animals, remove feces
Eimeria spp.
- “Coccidia”
* Only oocyst observedà clear outer ring surrounding a greyish center
Importance, Diagnosis, Control of Eimeria spp.
- Importance- Diarrhea
- Diagnosis- Oocysts in feces
- Control- Treat infected animals
Cysticercosis
formation of cysts outside of the GI system
Hydatid
fluid filled cyst
