Lecture 5: Swine Viruses 2 Flashcards
What are the features of porcine circovirus
- 4 types: PCV 1,2,3,4
- Endemic in commercial pig industry
- Makes 2 proteins
Features of PCV1
- PCV 1: low prevalence, first discovered
Location/features of PCV2
o In NA there are 3 genotypes (out of 8): 2b (most), 2a, 2d
o Difference in clincal or sub-clinical depends on type of PCV2/coinfection/host factors
What are consequences of subclinical infection from PCV2
o Subclinical: immunosuppression (can result in vaccine failure) = inhibited growth/susceptibility to pathogen/weight loss
What are consequences (clinically) of clinical infection of PCV2
o Clinical dz: due to high viremia = 80% mortality
Post weaning multisystemic wasting syndrome (PMWS)
PDNS: porcine dermatitis and nephropathy syndrome
SMEDI
* Reproductive failure (return to estrus/necrotizing myocarditis of fetus) – fetal cardiomyocytes targeted
Affect: systems - Respiratory/repro/enteric
Name 3 clinical manifestations associated with a porcine circovirus (PCV)2 infection.
Reproductive
Respiratory
Muscle wasting
Dermatitis
Poor Growth
An infection with porcine respiratory, reproductive syndrome virus (PRRSV ) will lead to immunosuppression-list 3 reasons. (3 marks
Target macrophages. Compromise function and reduce the number
Decoy epitopes that lead to a non-neutralizing antibody response
Slow cellular response
Glycan shielding protects antigen. Immunodominant epitopes create non-neutralizing antibody response
Which part of the gastrointestinal tract is affected by the enteric coronaviruses of pigs? (1 mark)
It affects mature enterocytes
Common viruses that cause porcine respiratory diseases are
A Herpesvirus and circovirus
B Rotavirus and parvovirus
C Circovirus and rotavirus
D Retrovirus and rotavirus
E Retrovirus and parvovirus
A
Porcine circovirus type 2 (PCV2) associated diseases (PCVAD):
A Include several syndromes in pigs such as post weaning multisystemic wasting
syndrome (PWMS) and porcine dermatitis and nephropathy syndrome (PDNS)
B Are restricted to skin lesions
C Are only observed in combination with vaccination
D Are endemic in North America and Europe but not in Asia
E Are associated with a low mortality rate and restricted to primarily young weaned
pigs
A
Porcine respiratory and reproductive syndrome virus (PRRSV):
A Induces antibodies with an unusual short half-life
B Induction of neutralizing antibodies is rather slow in comparison to other infections
C Does not cross the placenta
D Only affects immunosuppressed pigs
E Is impossible to eradicate from pig barns just by vaccination
B and E
Virus neutralizing antibodies (mark true):
A Are produced by T lymphocytes
B Bind to cellular molecules that translate mRNA molecules
C Prevent entry of viruses into the target cells
D Are a major component of some live attenuated vaccines
E Are strong inducers of innate immunity
C
Marker vaccine used for the control of Aujeszky Disease Virus
infection:
A Is unable to induce cell-mediated or antibody-mediated immune
responses
B Consists of porcine herpesvirus glycoprotein E gene inserted into poxvirus backbone
C Prevents respiratory signs but not abortion induced by the virus
D Differentiates vaccinated pigs from infected pigs
E Marks the injection site green due to the florescent tag of the vaccine
virus
D
Infection of pigs with porcine parvovirus:
A Results in acute and fulminant diarrhea
B Only significant in male animals (semen)
C Infects embryos and fetuses
D Cannot be prevented by vaccination
E Requires immediate culling of infected sows
C, D (can prevent disease not infection)
What are the clinical signs of post weaning multisystemic wasting syndrome (PMWS)
- Wasting/weight loss/resp or GI disorders/pale skin
- Lymphopenia, granulomatous inflammation of lymphoid tissue, PCV2 in lymphoid tissue > Target macrophages = lymphopenia/histiocyte replacement/intracytoplasmic inclusions
