Cryptosporidiosis and Coccidian Diseases Flashcards
Is cryptosporidium considered a coccidia?
NO
what type of cells do Coccidians and cryptosporidium infect?
GI tract & extra-intestinal sites
what genus are Coccidia?
Eimeria, Cystoisospora, Toxoplasma, Neospora, Sarcocystis, etc.
what is a zoite?
elongated, motile cell
what is an oocyst?
environmentally resistant stage
what does oocysts contain?
infective sporozoites, located within sporocysts
Are most cryptosporidium host specific or broad?
mostly host specific
what does cryptosporidium damage?
infect/damage mucosal epithelial cell
what type of life cycle does Cryptosporidium have?
direct
what type of transmission does Cryptosporidium that infect the GI tract have?
fecal-oral
what type of transmission does Cryptosporidium that infect the respiratory tract have?
droplet transmission
what is Schizogeny?
meronts divide -> merozoites -> infect host cells -> merontsm -> repeat
what is gametogeny?
subset of merozoites infect host cells and develop into gamonts -> gametes
what is fertilization?
zygotes -> ooxysts
what is the sporogeny of Cryptosporidium?
oocysts sporulate (sporozoites develop) endogenously (inside host)
what is a thin-walled oocyst?
sporozoites excyst and reinfect host
what is a thick-walled oocyst?
infective when shed, viable for months, resists disinfectants
Map out the life cycle of Cryptosporidium spp.?
oocyst ingested/inhaled -> sporozoites excyst -> infect host cells -> develop into meronts -> schizogeny -> gametogeny -> fertilization
what does gastrointestinal cryptosporidiosis cause?
gastroentereitis
what is seen in most hosts infected with gastrointestinal cryptosporidiosis?
mild to moderate, watery, self-limited diarrhea
what are the hosts of C. parvum?
ruminants, horses
what are the hosts of C. baileyi?
poultry
what is a large risk of C. parvum?
zoonotic, transmit to humans
what are the primary hosts of respiratory cryptosporidiosis?
avian hosts
what cryptosporidium causes respiratory and gastrointestinal cryptosporidiosis
C. baileyi
what are the symptoms of Respiratory cryptosporidiosis?
sinusitis, bronchitis, airsacculitis, pneumonia -> coughing, dyspnea, abnormal respiratory sounds
how do you diagnose Cryptosporidiosis?
clinical signs and…
microscopic ID of oocysts
ELISA
PCR
what is used to treat cryptosporidiosis?
nirazoxanide (calves)
paraomomycin (dogs and cats)
supportive therapy (main use)
how can cryptosporidiosis be prevented?
enforce strict sanitation and good management
isolate affected animals
what does Eimeria spp. largely impact?
ruminants and poultry
where do most Eimeria spp. infect? (location)
GI tract - enterocytes and/or cells in lamina propria
Are the predilection sites of Eimeria always the same?
no varies by species
what is the predilection site of E. tenella?
cecum
what type of life cycle does Eimeria have?
direct
How is Eimeria transmitted?
fecal-oral
what is the enteric cycle of Eimeria spp.?
schizogeny, gametogeny, fertilization, oocyst production
what is the sporogony of EImeria spp.?
oocysts typically sporulate exogenously (outside host)
what is the host of E. tenella?
chicken
what is the host of E. bovis?
bovine
Is there cross-infection between goats and sheep with Eimeria spp.? why or why not?
No b/c of strict host specificity
what do you see with Eimeria-induced coccidiosis?
enteritis (mild to moderate = damage to epithelium, severe = damage to epithelium and lamina propria)
diarrhes, fever, inappetence, dehydration, weight loss, emaciation, decreased production, death
what is winter coccidiosis?
severe cold provokes disease at even low infection levels
what is nervous coccidiosis?
enteritis + neurological disturbances, mainly seen in coldest months
how do you diagnose Eimeria induced coccidiosis?
clinical signs and…
microscopic ID - fecal float
what is the treatment of Eimeria-induced coccidiosis?
self-limiting - spontaneous recovery w/out treatment is common
anticoccidial drugs
supportive thearpy
what anticoccidial drug should be used to treat Eimeria-induced Coccidiosis in cattle?
amprolium
what anticoccidial drug should be used to treat Eimeria-induced Coccidiosis in small ruminants?
amprolium
what anticoccidial drug should be used to treat Eimeria-induced Coccidiosis in poultry?
amprolium
what is the preventention/control of Eimeria-induced Coddidiosis?
sanitation & animal management
isolate affected animals
prophylactic use of anticoccidial drugs
vaccines
what type of life cycle does Cystoisospora spp.?
direct life cycle with fecal oral transmission + transmission via paratenic host
how do paratenic hosts aid in the transmission of Cystoisospora spp.?
paratenic host ingests oocyst -> sporozoites encyst in lymph nodes & form tissue cysts -> infective to definitive host
what is the transmission of Cystoisospora spp.?
fecal-oral
where does Cystoisospora spp. infect?
GI tract - primarily infect enterocytes -> host cells ruptured/destroyed
Are Cystoisospora spp. host specific?
strictly host specific
what does Cystoisospora spp. infect?
GI tract - primary enterocytes, host cell ruptured/destroyed
what is the enteric cycle of Cystoisospora spp.?
schizogeny, gametogeny, fertilization, oocyst production
what type of sporulation does Cystoisospora spp. have - endogenous or exogenous?
exogenous sporulation
what is the Cytoisospora that infects swine?
C. suis
what is the Cytoisospora that infects dogs?
C. canis
what is the Cytoisospora that infects felines?
C. felis & C. rivolta
what are the definitive hosts of Toxoplasma gondii?
felids (wild and domestic)
How are felids typically infected with Toxoplasma gondii?
eating tissue cysts harbored by infected intermediate hosts
what is the enteric cycle of Toxoplasma gondii?
schizogeny and gametogeny in felid enterocytes -> oocysts shed in feces
How do oocysts sporulate for Toxoplasma gondii?
oocysts sporulate exogenously
what is the consequence of Toxoplasma gondii oocysts sporulating exogenously?
infective to intermediate hosts and felids
what is the extra-enteric cycle for intermediate hosts of Toxoplasma gondii?
tachyzoites develop in/rupture out of SI & mesenteric lymph node cells
what does tachyzoite explosion result in in intermediate hosts?
acute toxoplasmosis
what do tachyzoites form over time in intermediate hosts?
form tissue cysts containing bradyzoites in CNS, muscle, visceral organs
what are bradyzoites infective to?
felids and intermediate hosts
which phase has chronic toxoplasmosis?
tissue cyst phase
what species can exta-enteric cycle be present in?
mammals and birds
felids
which population of cats and dog get toxoplasmosis?
most common in immunodeficient adults and very young animals
what is a common cause of abortion and stillbirth in sheep and goats?
toxoplasmosis
what species are generally resistant to toxoplasmosis?
equids and cattle
how is toxoplasmosis diagnosed?
serological tests
ID tachyzoites
oocysts
how is toxoplasmosis treated?
clindamycin, pyrimethamine, sulfadiazine + pyrimethanie
supportive care
what does treatment of toxoplasmosis not eliminate?
bradyzoites in tissue cysts (chronic toxoplasmosis)
how is toxoplasmosis prevented/controlled?
sanitation & animal management
preventing hunting activity by cats
do not feed raw/undercooked meat or viscera to cats, dogs, etc.
sheep - live vaccine to prevent abortion and still birth
what are the definitive hosts of Neospora canium?
dogs, dingoes, wolves, coyotes
what are the intermediate hosts of Neospora caninum?
cattle, deer, other mammals
does Neospora canium have an enteric and extra-enteric cycle?
yes - similar to toxoplasma gondii
what causes the tissue damage and inflammation in Neospora caninum?
tachyzoites & tissue cysts
what are the disease patterns for dogs, cattle, and horses with Neosporosis?
dogs - subclinical infection
cattle - major cause of abortion, subclinical infection typically
horses - rare cause of EPM
what disease will have fetuses autolyzed in cattle?
Neosporosis
How is neosporosis diagnosed?
serologic tests
ID of tachyzoites
oocysts
How is neosporosis treated in dogs and cattle
dogs - clindamycin or trimethoprim sulfadiazine + pyrimethamine
cattle - no treatment
How is neosporosis prevented/controlled?
prevent dogs from eating bovine placental tissues, fetal membranes, raw meats
do not breed females w/ a history of clinical neosporosis or that welped affected pups
avoid glucocorticoids or other immunosuppressive drugs, to seropositive dogs
prevent contamination of livestock feed w/ dog
which Sarcocystis spp. is not host specific?
S. neurona
various mammals serve as intermediate hosts
what are the definitive hosts of Sarcocystis spp.?
carnivorous & omnivorous mammals, birds, reptiles
what is the mode of transmission of Sarcocystis spp.?
ingestion of tissue cysts (sarcocysts) in striated muscle of infected inermediate hosts
what is the enteric cycle of Sarcocystis spp.?
oocysts (endogenous sporulation -> sporocysts shed in feces
what are the intermediate hosts of Sarcocystis spp.?
mammals, birds, reptiles
how are intermediate hosts infected with Sarcocystis spp.?
ingestion of sporocysts
how do Sarcocystosis diseases present?
subclinical
what is seen in horses with Sarcocystosis?
equine protozoal myeloencephalitis (EPM)
what is seen in cows with sarcocystosis? which Sarcocystis spp.?
Cattle - S. cruzi - fever, anorexia, cachexia, decreased milk yield, diarrhea, muscle spasms, anemia, loss of tail hair, hyper excitability, weakness, prostration, abortion, death
what is seen in sheep with sarcocystosis? which Sarcocystis spp.?
sheep - S. tenella - fever, anorexia, decreased weight gain, anemia, weakness, loss of wool, myeloencephalitis w/ hindlind paresis or ataxia, abortion, death
what is seen in swine with Sarcocystosis?
weight loss, dyspnea, muscle tremors, purpura, abortion
how is Sarcocystosis diagnosed?
serological tests
ID schizonts, sarcocysts, and/or tissue cysts in post-mortem samples
how is sarcocystosis treated in horses, ruminants & swine, cats & dogs?
horses - ponazuril, diclazuril, sulfadiazine + pyrimethamine
ruminants & swine - therapeutic treatment ineffective
cats & dogs w/ neurologic disease - ponazuril, sulfadiazine + pyrimethamine, clindamycin
How is Sarcocystosis prevented/controlled?
prevent dogs & other carnivores from eating raw meat, offal, or dead animals
prevent contamination of livestock feed w/ feces of dogs, cats, opossums
keep dogs/cats/opossums out of building used to house lifestock
trap & relocate opossums
prophylactic amprolium for cattle & sheep
