Cryptosporidiosis & Coccidian Diseases Flashcards
Coccidia and Cryptosporidium infect…
GI tract and extra-intestinal sites
what are the life cycle stages of Coccidia and Cryptosporidium
zoites and oocyst
describe the zoite stage of Coccidia and Cryptosporidium
elongated, motile cell
invades host cell
INFECTIVE stage
names denote particular life cycle forms
describe oocyst stage of Coccidia and Cryptosporidium
environmentally resistant stage
shed in feces
contains sporocysts
what do Coccidia and Cryptosporidium sporocysts contain?
sporozoites aka form of zoite
what species does Cryptosporidium effect?
mammals, birds, reptiles, amphibians
Cryptosporidium epidemiology
most are host specific
infect/damage mucosal epithelial cells in GI tract, respiratory tract
predilection varies
describe the life cycle of Cryptosporidium spp. is it direct or indirect?
DIRECT
1. oocyst ingested/inhaled
2. sporozoites excyst
3. infect host cells
4. develop into MERONTS
5. schizogeny
6. gametogeny
7. fertilization and sporogeny
what is schizogeny?
meronts divide -> merozoites -> infect host -> meronts -» repeat
what part of the Cryptosporidium life cycle is indicated by the red arrow?
schizogeny
what is gametogeny?
subset of merozoites infect host cells and develop into gamonts -> gametes
what part of Cryptosporidium life cycle is indicated?
gametogeny
what is fertilization and sporogeny?
fertilization - zygotes that develop into oocytes
sporogeny - oocysts sporulate (sporozoites develop) endogenously aka inside host
what happens to thin walled oocysts during fertilization and sporogeny?
sporozoites excyst and reinfect host
auto-infection
what happens to thick walled hosts during fertilization and sporogeny?
infective when shed, viable for months, resist disinfectant
what part of Cryptosporidium life cycle is indicated?
fertilization and sporogeny
GI Cryptosporidiosis - gastroenteritis disease patterns
usually mild to moderate - watery D
severe form - persistent D, dehydration, weight loss, lethargy, anorexia
what is C. parvum?
GI Cryptosporidiosis in ruminants and horses
what is C. baileyi?
GI AND Respiratory Cryptosporidiosis in poultry
what is C. parvum?
ZOONOTIC GI Cryptosporidiosis in humans
Respiratory Cryptosporidiosis disease pattern
mainly in avian hosts
sinusitis, bronchitis, airsacculitis, pneumonia
how to treat Cryptosporidiosis?
Supportive care (fluids, electrolytes, nutrition)
meds not very effective
Eimeria spp epidemiology
VERY narrow host specificity
largest impact on domestic ruminants and poultry
most spp in GI tract
predilection varies
what type of life cycle does Eimeria spp have?
direct
enteric cycle = schizogeny, gametogeny, fertilization, oocyst
for Eimeria spp, sporology usually occurs…
exogenously (outside host)
Eimeria spp disease patterns
enteritis - epithelium damage (mild/moderate), damage to lamina as well (severe)
D, fever, weight loss, dehydrated, emaciation, decreased production
what is E. bovis?
cattle Eimeria spp
what is “winter coccidiosis” for cattle
Eimeria spp disease provoked by severe cold, even at low infection levels
what is “nervous coccidiosis” in cattle?
enteritis and neurologic disturbances, usually during coldest months
why is there NO cross infection between sheep and goats for Eimeria spp?
strict host specificity
what is E. tenella?
poultry Eimeria spp
how to diagnose Eimeria spp?
fecal float
how to treat Eimeria spp??
anti-coccidial drugs
AMPROLIUM and supportive therapy
Cystoisospora spp epidemiology
in all mammals, strict host specificity
typically in GI tract enterocytes
direct life cycle
how is Cystoisospora spp transmitted?
fecal oral
paratenic hosts
how do Cystoisospora spp paratenic hosts transfer the cysts to the definitive host?
paratenic ingests oocyst, sporozoites encyst in mesenteric lymph nodes, forms tissue cysts that are infective to definitive host
what does the red and blue mean regarding Cystoisospora spp?
red = enteric cycle - schizogeny, gametogeny, fertilization, oocyst
blue = exogenous sporulation
what is C. suis?
swine Cystoisospora spp
what is C. canis?
dog Cystoisospora spp
what is C. felis and C. rivolta?
cat Cystoisospora spp
Cystoisospora spp severity ___ with host age
decreases
Cystoisospora spp signs
most commonly D, dehydration, weight loss in young animals
Cystoisospora spp is diagnosed similarly to ____
Eimeria-induced coccidiosis
Cystoisospora spp treatment
TX swine is unreliable
Tx dogs/cats done via sulfadimethoxine
Toxoplasma gondii definitive host
felids (wild and domestic)
how are hosts typically infected with Toxoplasma gondii?
eating tissue cysts harbored by infected intermediate hosts
how do oocysts sporulate for Toxoplasma gondii within the definitive host?
exogenously
making it infective to intermediate hosts AND felids
what are the intermediate hosts of Toxoplasma gondii?
mammals and birds
since felids go through enteric cycle for Toxoplasma gondii, what type of cycle does the intermediate host go through?
extra-enteric cycle
describe the extra-enteric cycle of intermediate hosts for Toxoplasma gondii
tachyzoites develop in and rupture out of SI and mesenteric cells
tachyzoites infect cells throughout body
what is a tachyzoite “explosion” in regards to Toxoplasma gondii
acute toxoplasmosis
occurs when tachyzoites infect cells throughout body (includes placenta/fetus)
over time, tachyzoites of Toxoplasma gondii develop form ___ that contain ___ in CNS, muscle, and visceral organs
forms tissue cysts that contain bradyzoites
who are bradyzoites of Toxoplasma gondii infective to?
felids and intermediate hosts
describe the tissue cyst phase of Toxoplasma gondii
tissue cysts formed from tachyzoites
chronic toxoplasmosis, life long infection
can the extra-enteric cycle of Toxoplasma gondii occur in felids?
YES
can cause severe pathology
Toxoplasmosis disease pattern in young vs adult dogs/cats
most common in immunodeficient adults (endogenous AND exogenous)
young animals (exogenous)
congenital Toxoplasmosis is rare (would result in abortion or stillbirth)
signs of Toxoplasmosis in dogs/cats
pneumonitis, hepatitis, myocarditis, encephalitis, lethargy, C, dyspnea, anorexia, icterus
Toxoplasmosis disease pattern in small ruminants
common cause of abortion and stillbirth in sheep/goats
fever, anorexia, D, dyspnea, may die to enteritis
Toxoplasmosis disease pattern in swine
most common in piglets
congenital is rare (similar to dog/cat)
Toxoplasmosis disease pattern in equine and cattle
typically resistant
how to diagnose Toxoplasmosis
serology (ELISA)
ID tachyzoites and/or tissue cysts
are oocysts in feline feces correlated with development of Toxoplasmosis?
NO
how to treat Toxoplasmosis
what does Tx NOT eliminate?
Supportive care, Clindamycin
**Tx does NOT eliminate bradyzoites in tissue cysts (chronic)
who are the definitive hosts of Neospora caninum?
dogs, dingoes, wolves, coyotes
who are intermediate hosts of Neospora caninum?
cattle, deer, other mammals
Neospora caninum epidemiology in definitive hosts
ingest tissue cysts from intermediate host
has enteric cycle and extra-enteric cycle
Neospora caninum transmission in dogs
transplacental occurs sporadically
fecal-oral
Neospora caninum epidemiology in intermediate host
ingest sporulated oocysts
extra-enteric cycle
transplacental transmission
what causes tissue damage/inflammation in Neospora caninum?
tachyzoites and tissue cysts
Neosprosis disease pattern in dogs
usually subclinical
if disease - congential is most common (hindlimb paralysis, muscle atrophy)
adults have CNS signs, myocarditis, dermatitis, hepatitis
Neosprosis disease pattern in cattle
major cause of abortion BUT is suubclinical otherwise
fetus autolyzed at 4-6 months since transplacental transmission
Neosprosis diagnosis
serology
ID tachyzoites in CSF and/or tissue cysts
oocysts RARELY in dog feces
Neosprosis treatment in dogs
clindamycin
Neosprosis treatment in cattle
NONE
Sarcocystis epidemiology
TWO host life cycle
strict host specificity
who is definitive host of Sarcocystis?
carnivorous and omnivorous mammals, birds, reptiles
how are Sarcocystis definitive hosts infected?
ingestion of tissue cysts (sarcocysts) in striayed muscle of intermediate hosts
who are intermediate hosts of Sarcocystis?
mammals, birds, reptiles
how are intermediate hosts for Sarcocystis infected?
ingestion of sporocysts that are shed from host feces
extra-enteric cycle
what is S. neurona?
Sarcocystis of various mammals
*exception to the strict host specificity rule
Sarcocystis infections are typically ___
subclinical
Sarcocystis disease pattern in horses
causes Equine Protozoal Myeloencephalitis (EPM) via S. neurona
spinal cord lesions, brain lesions
Sarcocystis diagnosis done via…
serology
ID schizonts, sarcocysts, tissue cysts post-mortem
how would you diagnose Equine Protozoal Myeloencephalitis (EPM)?
testing CSF for antibodies along with serology tests
