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116 Cards in this Set
- Front
- Back
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General features of protozoan parasites |
-single celled organisms -small scale (microscopic) -parasitic in all tissues/systems of all vertebrates |
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Trophozoite |
the living, motile form of the parasite. does NOT want to leave the host |
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Why can't trophozoites survive outside the host? |
They are prone to dehydration and damage |
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What is the environmental transmission form of protozoa? |
the cyst/oocyst |
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What is the living motile form of protozoa? |
trophozoite |
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Cyst/oocyst |
environmental, transmission form of protozoa |
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What are the 2 major groups of protozoa? |
Flagellates and coccidia |
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What are the types of intestinal Flagellates |
Giardia and tritrichomonas foetis |
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What are the 2 subclasses of coccidia protozoa? |
Intestinal and blood |
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What are the intestinal coccidia protozoans? |
Eimeria, isospora, toxoplasma, and sarcocystis |
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What are the blood coccidia protozoans? |
babesia and cytauxzoon |
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Giardia sp. is associated with what? |
waterborne outbreaks (swimming pools, municipal water) |
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Giardia spp. lifecycle |
-direct life cycle -trophozoites multiple by binary fission in lumen of proximal SI -live free (extra-cellular) or attach via ventral sucking disk -cysts passed in feces -host infection via fecal-oral contamination and ingestion of cysts |
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How do Giardia spp. infect hosts? |
through fecal-oral contamination |
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Are cysts of Giardia directly infectious back to the host? |
yes |
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Is Giardia spp. symptomatic? |
yes and no. There are both symptomatic and asymptomatic infections |
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What are signs of a symptomatic Giardia infection? |
voluminous watery diarrhea, gas, flatulence, greasy stools that float, abdominal discomfort, anorexia, nausea, vomiting, weight loss, and fatigue |
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How long does illness from Giardia last? |
2-6 weeks |
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How do asymptomatic Giardia cases contribute to the parasite? |
They serve as a reservior and play an important role in transmission cycle to other animals |
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Which type of Giardia affects humans, livestock, dogs, cats, beavers, and guinea pigs? |
Assemblage A |
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What type of Giardia affects humans, chinchillas, dogs, beavers, rats, and siamang? |
Assemblage B |
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What Giardia species has different isolates for different hosts? |
Giardia duodenalis |
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12-15 by 7-10 micrometers |
Giardia sp. |
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12-15 by 7-10 micrometers |
Giardia sp. |
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How is Giardia diagnosed? |
by ZnSO4 flotation of fecals taken in 3 consecutive days. Giardia SNAP can be used in combination |
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How is Giardia treated? |
supportive care (especially in young animals) -restore electrolytes and combat dehydration -Panacur is one of the most effective drugs -bath pets at beginning of treatment |
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What do Giardia sp. look like under microscope? |
the 2 nuclei and the coma shaped median bodies show up prominently in tropozoa and cyst forms |
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Tritrichomonas blagburni |
flagellate protozoan parasite in large intestine of cats |
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What is tritrichomonas blagburni a causative agent for? |
chronic diarrhea (long duration can be weeks, months, or years) |
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Signs and symptoms of Tritrichomonas blagburni is cats |
chronic diarrhea but cats otherwise health (bright, alert, responsive) |
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What do Tritrichomonas blagburni look like? |
large nucleus and antenna looking things. You will see undulating membrane on direct smear |
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Tritrichomonas blagburni |
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Tritrichomonas blagburni |
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What is used to differentiate Tritrichomonas blagburni from Giardia? |
The sommersaulting movement of Tritrichomonas on direct smear. Direct smear is not effective in finding Giardia |
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How is Tritrichomonas blagburni diagnosed? |
-by direct smear (must differentiate from Giardia) -PCR specific assay |
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How is Tritrichomonas blagburni treated? |
-no FDA approved therapy -Ronidazole is effective but off label use -Metrinidazole is also effective |
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What is a concern when treating with Ronidazole and Metrinidazole? |
reversible neurotoxicity is a possibility |
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What must be broken in order to treat Tritrichomonas blagburni? |
The fecal-oral route of reinfection |
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Tritrichomonas foetus |
flagellate protozoan parasite in reproductive tract of cattle |
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Can different species of Tritrichomonas be distinguished under microscope? |
No. they are morphologically indistinguishable |
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What is Tritrichomonas foetus a causative agent for? |
bovine genital trichomoniasis |
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What does bovine genital trichomoniasis cause? |
infertility, spontaneous abortion in 1st trimester, and generalized repro tract infection |
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What animal is usually responsible for infecting other animals with Tritrichomonas foetus? |
Bulls. They are usually asymptomatic and pass it on to females |
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How is Tritrichomonas foetus diagnosed? |
PCR and culture methods |
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Trypanosomes |
blood and tissue flagellates |
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Trypanosomes are known as a causative agent for what? |
African sleeping sickness |
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What is the flagellate trophozoite stage of Trypanosomes circulating in blood known as? |
Trypomastigote |
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Anterior station mode of transmission |
Sailvarian, bite of infected "teste fly" |
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How are Trypanosomes further classified? |
By route of transmission. Anterior station or posterior station |
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Posterior station mode of transmission |
Sectorian, feeding rejuvidae bugs defecate and pass parasites |
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General Life cycle of Trypanosomes |
obligate indirect life cycle with arthropods as IH |
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Where do Trypanosomes develop into Trypomastigotes at? |
in IH |
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What stage of Trypanosomes multiply asexually in IH? |
epimastigotes |
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Where does Trypanosomes cause a lot of deaths? |
Africa |
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Trypanosomes |
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Trypanosoma cruzi |
causative agent of Chaga's Disease or American Trypanosomiasis |
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What is the causative agent of Chaga's disease? |
Trypanosoma cruzi |
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How do you get Trypanosoma cruzi? |
From Triatomin/ Reduviid bugs (obligate IH) |
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Where are Reduviid bugs commonly found? |
on raccoons, opossums, and armadillos |
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Romana's sign |
-get from Trypanosoma cruzi -edema and inflammatory response resulting from Trypomastigotes feces rubbed into eye |
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Romana's sign |
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How is Trypanosoma cruzi treated? |
There are no effective treatments |
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How is Trypanosoma cruzi diagnosed? |
PCR or serology |
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What are the signs of acute Trypanosoma cruzi disease in dogs? |
lymphadenopathy, myocarditis, pale mucous membranes, splenomegaly, tachycardia, etc. |
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Leishmania sp |
parasites infecting macrophages of vertebrate host |
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Where do developmental stages of Leishmania occur? |
Sand fly |
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How is leishmania transmitted? |
Sand fly bites |
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What species of Leishmania are associated with visceral disease? |
L. donovoni and L. infantum |
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Visceral disease of Leishmania |
amastigotes proliferate in macrophages and tissues -generally fatal |
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What Leishmania sp. are associated with muco-cutaneous diseas? |
L. mexicana (New World) |
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What Leishmania sp. are associated with cutaneous disease? |
L. tropica (Old World) |
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muco-cutaneous form of Leishmania |
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Visceral Form of Leishmania |
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Dog with Leishmania |
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What is seen in a dog with Leishmania? |
severe cutaneous manifestation (not seen in humans) |
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Is Leishmania zoonotic? |
Yes. Infected dogs serve as an open reservior for sand flies to pick up parasite and transmit to humans |
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Why is Leishmania not seen often in the US? |
Spot-on/ permethrin flea control products repell flies |
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What is the stage that leaves the host in all Intestinal Coccidia? |
an oocyst |
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What are the 4 classes of Intestinal Coccidia (Class sporozoa) |
Eimeria, Isospora, Toxoplasma, and Sarcocystis |
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Eimeria sp. |
-direct life cycle (ingestion of sporulated oocysts) -infects domestic livestock, birds, grazing wildlife -asexual replication in SI -diarrhea associated with destruction of enterocytes -sexual reproduction in free uninfected cells of LI |
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Describe Eimeria sp. replication |
-asexual replication in SI -Sexual replication in LI producing oocysts that are passed in the feces |
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What is disease associated with in Eimeria sp. |
asexual replication within host tissues! |
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How many sporocysts and sporozoites are in an oocyst of Eimeria sp? |
4 sporocysts with 2 sporozoites |
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sporulated Eimeria oocyst |
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Eimeria oocyst |
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Eimeria oocyst in sheep fecal |
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What are some key structures in identifying Eimeria oocyst? |
-polar flug (a.k.a. micropile) -details of the cyst wall...very thick |
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Can you have a negative fecal exam on an animal infected with Eimeria sp? Why? |
Yes because disease is associated with asexual replication in host tissues. This does not produce oocysts to be passed in the feces |
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What are the clinical signs of Eimeria sp? |
scours |
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How are animals infected with Eimeria sp? |
eating sporulated oocysts that are passed in the feces |
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Is it practical to disinfect for Eimeria sp? |
No. Oocysts are hardy and resistant. Good hygiene is the best prevention |
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Cystoisospora sp. Life cycle |
-facultative direct/ indirect life cycle -ingestion of sporulated oocysts -infects cats, dogs, pigs, and some birds |
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What is the paratenic host for Cystoisospora? |
mice, birds, and rodents |
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What does the oocyst of Cystoisospora look like? |
2 sporocysts each with 4 sporozoites |
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Where/how do Cystoisospora reproduce? |
sexual and asexual replication in the SI |
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what are the clinical signs of Cystoisospora? |
diarrhea due to destruction of enterocytes |
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What animal is Cystoisospora most commonly seen in? |
puppies. You should not be seeing oocysts in dogs that are over a year in age |
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Cystoisospora oocyst |
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What is another name for Cystoisospora? |
Isospora |
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What are the 2 species of Cystoisospora that infect dogs? |
C. canis and C. ohioenis |
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40 by 30 micrometers |
Cystoisospora canis |
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What does the oocyst look like in C. canis and C. felis? |
tear dropped shape and measures about 40 by 30 micrometers |
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What does the oocyst of Cystoisospora ohioensis and C. rivolta look like? |
round shape measuring about 20 micrometers in diameter |
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25 micrometers in diameter |
Cystoisospora rivolta or C. ohioensis |
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What are the two types of Cystoisospera that infect cats? |
C. felis and C. rivolta |
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What are some steps in management of intestinal coccidia infections in companion animals? |
-diagnosis by sucrose flotation -supportive care -off label use of Ponazuril in dogs and cats -bathe pet at beginning of treatment protocol to remove infective cysts -remove feces daily |
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Cryptosporidium spp. is associated with what? |
waterborne outbreaks (swimming pools and municipal supplies) |
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What is the major concern with Cryptosporidium sp? |
There is a zoonotic risk for vets especially those working around dairy cattle |
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What is the most wide spread sp of Cryptosporidium? |
C. parvum. readily infects humans, cattle, cats, dogs, deer, rabbits, and other wildlife |
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Is Cryptosporidium killed by chlorination or bleach? |
No |
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Cryptosporidium sp. life cycle. |
-direct life cycle -sexual and asexual replication occur in the small intestinal epithelium (intercellular) |
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How is the host infected with Cryptosporidium spp? |
fecal-oral...ingestion of oocysts |
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Cryptosporidium sp. oocyst |
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What are the clinical signs of a symptomatic infection of Cryptosporidium? |
voluminous watery diarrhea (mucous present, rarely blood/leukocytes), abdominal discomfort, anorexia, nausea, vomiting, weight loss, fever, fatigue |
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When should Trypanosoma cruzi be a differential diagnosis for dogs? |
presenting symptoms of cardiac disease and infection, travel history that includes central/South America, outdoor residence/hunting dogs, association with kissing bugs |
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When should Leishmania infection be a differential diagnosis? |
presenting with symptoms of dermatologic disease/infection and travel history that includes Central/South America or Europe (especially Mediterranean region) |
