Parasit - Lab Quiz 3

dslemeraldcity's version from 2016-09-21 23:12

Cryptosporidium (means "naked sporozoite")


Question Answer
Is Cryptosporidium Zoonotic?YES Infects 22 species!! Notifiable in GI illnesses in U.S. for humans. Not all species of Cryptosproidium are zoonotic. Community wide outbreaks common during late summer! (swimming in infected pools!)
Morphology of Cryptosporidium OocytesVery thick walled oocyst. Contains 4 sporozoites 22 species!
What is the transmission process of Cryptosporidium?DIrect & Autoinfection Fecal-oral --> Water or Food. RESISTANT TO CHLORINE!(Don't swim with diarrhea!) Mucosal scrapings and tissue homogenates from infected organs, Mechanically in non-living materials(boots, equipment)
When does the Cryptosporidum Oocyst sporulate & how long does it remain viable?The Oocyst sporulates(infective life stage) BEFORE it leaves the host & can remain viable outside of the host for several months because the Oocyst are stable in environment and resistant to most disinfectants. Freezing, heating or thorough drying can kill them.
Where do most Cryptosporidium Oocytes replicate & spend the majority of their life cycle?In the microvillus borders of enteric epithelial cells of the host, but also found in the gallbladder, respiratory system, and kidneys in immunocompromised hosts. (Life threatening in immune-compromised individuals!)
What is the most common seen Clinical Sign of Cryptosproidium?Diarrhea!
Which animals are know to be carriersPIGS
How does Cryptosporidium present in Calves(<1month old)?1-2 days PPP(pre- patent period). Diarrhea can be mild & transient to projectile severe & yellow with maybe blood, mucus or gas bubbles. Lethargy, fever, anorexia & possible CNS signs when infected with respiratory cryptosporidium. High morbidity with occasional mortality– C. parvum
How does Cryptosporidium present in Lambs & Goat kids?Similar, but more severe than calves. Infect distal portion of small intestine, cecum & large intestine.
How does Cryptosporidium present in Foals?Diarrhea in up to 80% <6 months old. Life-threatening if immunocompromised(SCIDs in Arabians!), Endogenous stages found in small intestine, stomach, bile, pancreatic ducts. – C. parvum
How does Cryptosporidium present in Pigs?Zoonotic! Seldom show signs of enteritis or colitis, some signs of mild inflammatory lesions present. – C. suis
How does Cryptosporidium present in Dogs?Zoonotic!(Ferret genotype) Dogs are more resistant unless immunocompromised(parvo pups) – C. canis
How does Cryptosporidium present in Cats?Zoonotic!, Anorexia, weight loss, diarrhea. Acute Renal Failure in Cats Treated with Paromomycin – C. felis
How does Cryptosporidium present in Snakes?Chronic wasting. Hypertrophic gastritis(swollen stomach). Mucsoal folds thickened with numerous pinpoints of foci hyperemia. Poor prognosis, Cull infected snakes.
How does Cryptosporidium present in Poultry?Can infect Anywhere pretty much! Proventriculus, conjunctiva, nasopharynx, larynx, trachea, bronci, small and large intestine, ceca, bursa of Fabriscus, cloacae, and kidneys – C. parvum
How does Cryptosporidium present in Humans?Life threatening in immunocompromised humans(AIDS). Watery diarrhea, cramping, abdominal pain. Flatulence, weight loss.
How do you diagnose Cryptosporidium?Acid Fast Stain!, PCR, Immunomagnetic Separation(IMS)(used primarily in research) Immunohistochemistry(IHC), IFA, ELISA



Question Answer
Morphology of Sarcocystis?Thick walled Sporulated Ooocyst in feces.

Sporozoites invade muscle tissue & form Sarcocysts containing the Bradyzoite form.
Do Sarcocystis require an intermediate host?YES
What species are the Definitive Host for Sarcocystis?Humans, dogs, cats -Predator
What species are the Intermediate Hosts for Sarcocystis?Ruminants, swine & horse (also armadilo, raccoon, skunk, cats, & sea otter) -Prey
What Life Cycle does the Sarcocystis require?INDIRECT! Obligatory 2 hosts(heteroxenous) via Predator-Prey life cycle
What is the Infective Stage of the Sarcocystis?The ingestion of the sarcocyst in undercooked meat & Sporulated Oocysts
How is Sarcocystis Transmitted to IH & their DH?IH Fecal-oral when grazing in area contaminated by Sporulated Oocysts from DH feces. DH via Predator-prey, when the DH eats an IH that contains Sarcocysts in their skeletal or cardiac muscle.
What are the Pathological phases of Sarcocystis infection?Acute & Chronic
What is the Acute Phase associated with?IH, Occurs in 1-3weeks, Associated with Tachyzoites(rapid dividing in cells-NOT in RBCs)
What is the Chronic Phase associated with?IH, fromation of cysts (Sarcocyts) containing Bradyzoites(slowly dividing in cysts)
What are the Clinical Signs of Sarcocystis in Cattle?Abortion in last trimester, Intermittent fever, Decrease in milk yields, Dyspnea, Anorexia, Hemorrahagic Vaginitis, Excessive salivation, Diarrhea
What are the Clinical Signs of Sarcocystis in Sheep?Abortion, anorexia, ataxia and death, possibly Encephalomyelitis
What are the Clinical Signs of Sarcocystis in Pigs?Poor growth, diarrhea, myositis, lameness
What are the Clinical Signs of Sarcocystis in Humans?Nausea, vomiting, abdominal pain, diarrhea, fever, myalgia, bronchospasm, eosinophilia – Do not eat undercooked meat!!
What are the Clinical Signs of Sarcocystis in Horses?Horses are dead-end(aberrant) hosts similar to Marine animals these days.(IHs Not regularly consumed) Equine Protozoal Myeloencephalitis(EPM) presents as #1 cause of neurological signs in horses-Head tilt, wide stance, ear drooping, ptosis, dysphagia, muscle atrophy, depression & nerve paralysis of varying degrees. Severity DIRECTLY related to # of Sporulated Oocytes ingested( – S. neurona)
What causes Equine Protozoal Myeloencephalitis(EPM) in Horses?S. neurona. Not all horses exhibit clinical signs, but stress may worsen the conditions
How do we Diagnosis Sarcocystis in DH?Most are asymptomatic, but sporulated oocysts(sporocysts) can be seen in fecal floats, or observed in biopsy or necropsy.
How do we Diagnosis Sarcocystis in IH?Presence of schizonts in endothelial cells, brain, or spinal cord, OR presence of sarcocysts in skeletal and cardiac muscle in biopsy or necropsy. Also check History of exposure to DHs.
What are some other ways to Diagnosis Sarcocystis?Western Blot of CSF, IFAT, Elisa(Ab) & Avidin-Biotin Immunohistochemical Staining(immunohistochemistry). -False positives when blood is present.
Which tests are not considered diagnositic for Equine Protozoal Myeloencephalitis(EPM)?IFAT & Elisa(Ab) bc of high prevalence of sarcocystis species that cross react with S. neurona
What test is considered the Gold Standard for diagnosing Sarcocystis?NONE! Necropsy is the ONLY definitive test!
How do you Control Sarcocystis?Dead livestock should buried or burned. Encourage clients to not feed raw meat to dogs and cats --> unless frozen to kill cyst stage. Successful treatment for EPM defined by negative CSF Western Blot & then administration of Sulfadiazine, Supplement with folic acid or Nitrazoxanide