Parvovirus Flashcards
Parvo did not exist until
1978
Parvoviral DNA
Small, single linear strand
- only codes for 4 proteins
- positive polarity
Parvoviral structure
Icosahedral
- size varies from 18-24 nm
- contains no lipid or carbohydrate
Parvovirus replicates in the ______
Nucleus
- exhibits naked infectivity
- replication enzymes are coded for and supplied by the host cell
What form of parvoviridae infects invertebrates and insects?
Densovirus
- problem with circket producers
Cat
FPV
- panleukopenia causing enteritis, teratogenesis, cerebellar hypoplasia, or aplasia
Dog
CPV, MVC
- parvovirus causing enteritis, myocarditis
Pig
PPV
- mummified, aborted fetus
Cow
BPV (HADEN virus)
- enteritis, reproductive disease
Mink
Mink enteritis virus, Aleutian disease virus
- enteritis, plasmacytosis, hypergammaglobulemia
Rabbit
RPV
- no clinical signs, is an orphan virus!!
Rodents
RV, H-1, H-3, H-14, Minute virus of mice
- teratogenesis, cerebellar ataxia
Man
Norwalk agent, B-19
- gastroenteritis, aplastic crisis, exanthema, Fifth disease, polyarthralgia, hydrops fetalis
Horse
Questionable, no clinical signs
What are the 8 general steps in the infection of host cells?
- attachment: via specific receptor on cell surface
- penetration: receptor mediated endocytosis
- uncoating: eclipse and release of viral nucleic acid
- transcription: formation of mRNA
- translation: mRNA to protein
- replication
- assembly: core proteins associate with NA, capsomeres follow
- release: enveloped virus gain lipid bilayer, cytocidal or persistant infection results
Is parvo an enveloped virus?
No
What cells are parvo cytocidal to?
Rapidly dividing cells (stem cells)
- causes rapid infection
Infectious GI diseases rank second in occurrence to ________
Infectious respiratory diseases
My GI viruses cannot be _______
Cultured
What is responsible for the development of diarrhea?
Cell functional changes
Localized viral GIT infections
Involve specific cellular tropisms
What are viruses affected by in the GIT?
Trypsin
- cleaves lys-arg bonds
What 2 viruses have enhanced infectivity by trypsin?
Rota and coronaviruses
Most GI viruses are ______ resistant
Acid
Some systemic GIT are ______ resistant
Acid, utilize a viremia to circumvent the low pH of the stomach
What cells to parvovirus first infect?
Cells of the tonsil, gain entry into circulation and travel via a plasma associated viremia to the crypts of intestinal mucosa
Why are young animals more susceptible to parvo?
- low stomach acidity
- low immunity
- abundance of rapidly dividing cells
Mitolytic viruses kill mitotic cells via
Chromosome pulverization
In utero exposure
Fetal death
- abortion
Neonatal exposure less than 8 weeks old
- <2 weeks old: generalized infection and acute death
- 3-8 weeks old: localized infection, myocarditis, death
Oronasal exposure greater than 8 weeks old
Regional lymph node, pharynx, tonsil infection leading to viremia plasma-associated spread to lymphoid tissue, intestinal cells, and lungs/liver/kidney
What infected organs cause minimal pathology?
Lungs, liver, kidney
Parvo is a _____ infection
Persistent, will have it for life
- low levels, cannot transmit to other dogs but will stimulate an immune response
