Cryptosporidia Flashcards
general features
intracellular parasites
-intestinal epithelium
-endothelium blood vessels
-organs and other tissues
gliding locomotion
trophozoites with apical complex
asexual and sexual replication
-schizogony (asexual) and gametogony (sexual)
1 host lifecycles
monoxenous
may use paratenic host
2 host lifecycles
heteroxenous
obligate and facultative indirect
cryptosporidium spp
primarily associated w waterborne outbreaks, daycare centers, foodborne outbreaks, occupational risk
metabolically divergent from other apicomplexa
host specificity variable
oocysts passed in feces, immediately infective and morphologically indistinguishable
able to survive in environment and water treatment
metabolically divergent from other apicomplexa
pathways show similarity to bacteria
lack krebs cycle, unable to synthesize fatty acids
lack plastid bodies for manufacturing food
unresponsive to anti coccidal drugs
cryptosporidium spp lifecycle
direct
sexual and asexual replication in small intestinal epithelium
oocysts passed in feces after 3-5 incubation
immediately infective
fecal-oral ingestion of oocysts
few as 9 oocysts infective
symptomatic infections
voluminous water diarrhea
mucous present, rarely bloody
abdominal discomfort, anorexia, nausea, vomiting, weight loss, fatigue, fever
mean illness duration 12 days
may be self limiting if immunocompetent
cryptosporidium spp in animals
dairy cows
1-3 weeks of age
early separation from dam
incubation period avg 4 days
anorexia, profuse diarrhea, weight loss
horses, pigs, companion animals infection usually inapparent
health issues in animals: neonatal calves
1st weeks of life
multiple causes (viral, bacterial, parasitic)
cryptosporidium ~25% of all deaths attributed to scours
malnutrition, reduced growth
-blunting of brush border, loss of microvilli
-decreased milk production
oocyst contamination of bedding
-source of reinfection
health issues in animals: sheep and goats
young and immune naive animals
reduced carcass weight, fiber production
health issues in animals: companion animals
occasionally seen in dogs and cats
genetically distinct
species specific
generally asymptomatic
zoonotic in immunocompromised people
health issues in animals: birds, wildlife, swine, snakes/lizards, etc
all species specific
minimal zoonotic risk
cryptosporidium spp therapy in animals
no consistently effective approved pharmaceutical
not cost effective for use in cattle and calves
supportive care to restore electrolyte imbalance from diarrhea!!
cryptosporidium spp disinfection
chlorine not effective
ammonia compounds appear most effective
oocysts in milk and water killed by commercial pasteurization
what is a phrenological drug target for cryptosporidium
apicoplast
