Viral Gut Diseases Flashcards
(33 cards)
What are the two main species of parvovirus?
- Canine parvovirus
- Porcine parvovirus
What are the pathological features of parvovirus?
- Has a single stranded DNA genome
- icosahedral capsid
- non-enveloped which means it can survive well in the environment
How long is the parvovirus genome?
4-6kb long
Where does the parvovirus genome replicate?
It replicates in the nucleus
doesn’t encode its own replication enzymes
During what phase of the cell cycle does parvovirus replicate?
DNA replication occurs in the S phase
What are the general characteristics of parvovirus?
has a small genome, this means that small changes have large consequences
and it requires rapidly dividing cells
What are the preferential replication sites for parvovirus?
- Intestinal crypt epithelial cells (adult hosts).
- Foetal lung and liver.
- Bone marrow cells (important in diagnosis)
How is parvovirus transmissed?
foecal-oral route
Large quantities of virus particles are released into the environment in faeces
Infection of new hosts is via the oral route
What plays an important role in the transmission of parvovirus?
Fomites
e.g farm setting in poultry and kennels in dogs/cats
What is the pathogenesis of porcine parvovirus?
It is a global issue in pig farms (enzoonotic)
has a rapid and widespread transmission
* causes mild diarrhoea in adults
*
How does porcine parvovirus enter the foetus?
via infected macrophages
then has a rapid growth in the foetus
When is the virus excreted in the foetus?
10-14 days post infection
How may you diagnose PPV?
Tissue faecal sample
-test for the virus isolation in tissue culture
Blood/Serum
-* Haemagglutination Inhibition test (HIT).
* Capsid proteins of PPV agglutinate red
blood cells
* ELISA
From what virus did canine parvovirus evolve from?
Feline panleukopeania virus
What are the clinical signs of feline panleukopaenia virus in adult cats?
- Fever
- Profound depression
- Rapid and severe weight loss
- Dehydration followed by vomiting
- Diarrhoea 1-2 days later
- abdominal pain
What are the clinical signs of feline panleukopaenia virus in kittens?
- sudden onset depression
- jaundice, vomiting, diarrhoea
- up to 90% mortality ‘
*
How may you diagnose feline panleukopaenia?
Faecal and Blood Sampling, both using ELISA tests
How can Feline parvovirus be treated?
Supportive therapy e.g
* Hospitalisation
* IV replacement of fluids and electrolytes
How can you control feline parvovirus?
biosecurity wise
- Virological properties make it very difficult to exclude from catteries etc
- Bleach (hypochlorite) 3% :
- but its rapidly inactivated by organic material.
- Quarternary ammonium compounds ineffective.
How can you control feline parvovirus?
vaccination wise
- Inactivated, modified live or multivalent vaccines.
- Newborns are protected by maternal antibodies – wane around 4-6 wo.
- May be a small window of susceptibility prior to first vaccination.
- Most frequent reason for vaccine failure is maternally derived antibody (MDA) interference.
- Example vaccination:
- Kittens at 6-9 wo, booster at 10-12 wo and 16-18 wo then annually
What are the two forms of canine parvovirus?
- Enteric Form
- Cardiac Form
What is the incubation period of canine parvovirus?
3-14 days
What are the clinical signs of the enteric form of canine parvovirus?
- Sudden depression and loss of appetite.
- Fever (esp. in puppies).
- Vomiting and diarrhoea – can be haemorrhagic.
- Rapid dehydration.
- Shock and death (acute cases).
What are the clinical signs of the cardiac form of FPV?
- Damage during development, symptoms
after birth. - Dyspnoea (laboured breathing).
- Depression.
- Cough.
- Ascites (fluid in abdomen).
- Death typically 12-16 wo.
