Cryptosporidiosis, Toxoplasmosis, Besnoitiosis, Sarcocystis

Question 1

Cryptosporidium parvum

Cryptosporidium Muris

Answer 1

*Many sp, esp. calves 1-3w , ZOONOSIS!
*Mild/subclinical - no symptoms
1. Clinic signs: actue diarrhrea orwatery/pasty feces with mucous shred
*C.parvum: anorexia,fever,DH, DEATH.
2. Diagnosis: i.floatation method, 5-8 um sporulated oocysts, eliptical/spherical with obscure internal structure (4 sporozoites)
ii. Oocysts in smear of mucosa/feces + staining (Kinyoun, Ziehl-Neelsen, safranin-methylene blue, giemsa; oocyst-red)
iii. Classical biological characteristics (e.g host specifity): expensive+ time consuming
iv. Immunological methods: IF + Monoclonal antibodies, ELISA,RPH. (Cross reaction can be problematic)
v. Molecular techniques: PCR (false + from naked nucleic acid/other microorganisms/contamination)
3. Necroscopy: enteral catarrh in ileum, l. Propria infiltration with cryptosporidium stage (brush border).
C. Muris=> signs in digestive gl. Of abomasum

Question 2

Cryptosporidium Baileyi

Cryptosporidium meleagridis

Answer 2

Birds, mild/sub-clinical: no symptoms

• Airborne infection, respiratory symptoms (sneezing, coughing, dyspnoea,nasal discharge, conjunctivitis), rarely diarrhrea.
• Same diagnosis method
• Necroscopy: air sacs inflammation, pneumonia,sinusitis , hiso changes in intestine,cloaca,bursa fabricus, trachae

Question 3

Toxoplasma Gondi

Answer 3

ZOONOSIS! Final host: Felidae sp. , Intermediate hosts: mammals+birds

1. Clinical signs: latent without any clinical signs (eyes, CNS, heart)
   * Cat: rarely encephalitis, enteritis , pneumonia
   * Dog: rarely anorexia, diarrhrea,pneumonia,CNS symptoms
   * Eq: rarely nervous signs (e.g: imparied vision)
   * Pregnant ewes: abortion (1st half/still born/weak foetus)
   * Su: acute phase: rarely fever, apathy , diarrhrea, respiratory distress and CNS symptoms, Abortion.
   * Pregnant women: abortion, premature delivery, still born, mental disorders, blindness of baby.
2. Diagnosis:
   i. ONLY IN CAT unsporulated oocysts (ca 10x12) with floatation method. Patency max 20 days. Sporulated: 2 sporocyst , 4 sporozoites each => indistinguishable from oocysts of HAMMONDIA HAMMOMDI.
   ii. Immunodiagnostical: SABIN-FELDMAN dye test (Ab disable staining tachyzoits by methylene-blue) , complement fixation test (less reliable in bo,su,po) , ELISA,IHAT, IFAT,
   iii. Demonstration of Toxoplasma: biopsy/CSF/IFAT tachyzoits, cyst (20-100 um,round,thin-walled)
   iv. Tissue culture
   v. Mouse inoculation test: tachyzoites in ascites after 5-10d , cysts in brain in 20-30d (RH strains: no cyst , kill all infected mice in 4-7d)
   vi. PCR from CSF, neuroimaging with tallium-201 brain single photon emission CT
3. Necroscopy: extraintestinal: retained/mummified aburted foetus of SHEEP/GOAT, yellowish necrotic spots in placenta, brain lymphatic infiltration, necrotic foci+granulomas in liver,spleen,lung,brain. Rabbit: disseminated toxoplasmosis. Young Dogs: dissiminated in conjunction with Rubrath’s disease, canine distemper: necrotic inflammatory foci with cysts. (Rare: pneumonia,enlarge mesenteric ln, encephalitis)

3.

Question 4

Besnoitia Besnoiti - cattle Besnoitiosis

Answer 4

Cattle- intermediate host, unknown final host.
*Cystozoites can be transmitted mechanically by blood sucking flies (Tabanus,stomoxys)
1. Clinical signs: majority-asympomatic. Acute: anorexia, fever , swollen ln,rihinitis, dyspnoea,SC oedema.
Chronic: skin thickening, wrinkling, alopecia, abortion in cows , sterility in bulls (testicular infection)
2. Diagnosis: cysts in sclera, conjunctiva, respiratory+genital mucousa, skin biopsy, serology
3. Necroscopy: macroscopically visible cysts (6-800) on serous/mucous. Histo: nuclei: thin, outer: thick

Question 5

Sarcocystiosis

Answer 5

Final host: carnivore + man - intestinal form
Intermediate hosy: Ru,su,eq,rabbit+ muscle form
1. Clinical signs: ca- no signs even in heavy infection
Man- acute GI malaise, 2-3w diarrhrea, vomiting, shivering, sweating
Cattle- Dalmeny disease” -abortion. intermittent fever attacks, emaciation, exophthalmos, anaemia, reduced milk,LN elargement
Lambs- anorexia ,death, abortion+ anaemia in pregnemt ewes S. Ovicans
Swine- high conc- biphasal fever btw 5-9d and 11-15d post infection, 2nd phase- apathy, dyspnoea, anaemia, cyanosis, muscle spasm, abortion.
1. Diagnosis:
* final hosts: sporocyst ( 12-16 um ca, 10-12 fe -4 sporozoites) or sporulated oocyst (2 sporocysts)- flotation method + identification of the species.
*Intermediate host: Ag- cystozoite derived from in vitro cultures of schizonts and merozoites. serodiagnostic (ELISA, IFAT)is not reliable.
2. Necroscopy: variable cyst size. Sheep- wheat-pea size , greyish yellow sarcocysts of s. Gigantea in esophagus. Bo+eq: Hirsuta/equicanis (8)- naked eye
Haemorragic diathesis, enlarge ln, necrotic lesions in liver, kidney , heart.
Myositis sarcosporidiaca: Small necrotic cysts (discoloration, oedema and fibrosis) in tongue, heart , esophagus, skeletal m. . Merozoites+schizonts in smears and histological section with immunochemistry , cystozoites (12-15, banana shaped) in meat , DNA probes