L23: Parvoviruses/Circoviruses of Domestic Species (Waltzek) Flashcards
structure of parvoviruses***
- small icosahedral
- ssDNA
- NO ENVELOPE –> ENVIRONMENTALLY RESISTANT!**
where do parvoviruses replicate?***
in nucleus of RAPIDLY DIVIDING CELLS (i.e. GI crpyt cells, lymphocytes)
-form EOSINOPHILIC INTRANUCLEAR INCLUSIONS**
Name 6 parvoviruses of interest
Porcine parvovirus Feline panleukopenia virus Canine parvovirus Mink enteritis virus Aleutian mink disease virus Goose parvovirus
Porcine parvovirus causes what disease processes?
SMEDI syndrome (Stillbirth, mummification, embryonic death, infertility)
SMEDI in Pigs
- naive gilts bred to new boars most susceptible
- fetuses born weak or stillborn
- immune to subsequent infection
- virus in boar semen, testicles, feces
- very resistant in env.
- diagnosed best with mummified fetus
- prevent with vaccines (maternal Ab can interfere)**
How can maternal Ab interfere with vaccine schedule?***
if vaccine given at wrong time (before maternal Ab wear off), vaccine will be ineffective because maternal Ab will destroy the vaccine and prevent immunity
feline panleukopenia virus causes what disease processes?
cerebellar hypoplasia
panleukopenia
enteritis
feline panleukopenia chars. (including CS)
(parvovirus)
- highly contagious, fatal (esp. in young cats)
- direct/indirect/vertical transmission
- virus shed 6wks after clinical infection clears
- CS: either HIGH fever and sudden death, or lethargy, hypothermia, bloody d, etc.
- in utero infection causes cerebellar hypoplasia, stunted growth**
tx and prevention of feline panleukopenia virus
- TX: supportive care only: fluids, electrolytes, abx, +/- antiemetics/H2 receptor antagonists/sucralfate
- Prevention: vaccination, disinfect env. with BLEACH
What type of vaccines should be avoided in sick/pregnant animals?
Modified vaccines
Canine parvovirus causes what disease processes?
generalized neonatal dz
enteritis
myocarditis
panleukopenia
T/F: canine parvovirus still an important cause of d in wild/domestic canids?**
T
canine parvovirus most common in which dog breeds?**
Rottweilers Dobermans Labs American Staffordshire Terrier German Shepherd Alaskan sled dogs
CS of parvovirus
- type of diarrhea depends on which cells/portion of cells are affected in the GI**
- enteritis, sepsis, death
- myocarditis in young puppies
canine parvovirus prevention
- vaccination (before and after maternal Ab wear off)
- disinfect with bleach
- reduce exposure
What are the two main exceptions to virus inclusions?***
1) Poxviruses: in nucleus
2) circoviruses in cytoplasm
circovirus structure
- small ssDNA virus
- NO envelope
- icosahedral shape
- intracytoplasmic and intranuclear inclusion bodies
where does circovirus replication occur?**
rapidly dividing cells
Name 3 circoviruses
porcine circovirus 2
psittacine beak and feather disease virus
chicken anemia virus
Porcine circovirus 2 assoc. with what dz?
- Postweaning polysystemic wasting syndrome
- Also causes emaciation, hemorrhagic epidermitis, resp. dz
Postweaning polysystemic wasting syndrome
- effects piglets
- targets macs and lymphocytes
- high mortality
- a complex dz
Dx of Porcine Circovirus 2 assoc. disease**
- quantitation of viral load by qPCR (quantitative PCR) in lymphoid cells is important
- immunohistochemistry and immunofluorescence of affected tissues
Management of Porcine Circovirus 2 assoc. dz
- don’t allow co-mingling
- use AI from dz free boars
- increase weaning age
- enough colostrum
- inactivated (subunits) vaccines effective
Psittacine beak and feather disease virus causes what disease?
Psittacine beak and feather disease
Psittacine beak and feather disease
- targets growing cells of feather follicles, beak, claws young birds -> necrosis/feather malformation
- “botyroid” basophilic intracytoplasmic inclusions in epithelium formed
- one of primary reasons for feather loss in birds
- progressive, immunosuppressive
- highly infectious (vertical and horizontal)
- No vaccine
Chicken anemia virus causes what disease?
Chicken anemia virus disease
Chicken anemia virus disease
- resistant to disinfectants
- transmitted vertically via egg and horizontally
- only specific sign = ANEMIA**
- live modified vaccine
