Circoviridae Flashcards
What are the 2 genus that fall under Circoviridae?
- Circovirus
2. Gyrovirus
3 diseases caused by Circoviruses
- Psittacine beak and feather disease
- Porcine Circovirus type-1
- PCV-2 (PMWS)
1 disease caused by Gyroviruses
Chicken infectious anemia virus
T/F Viruses belonging to Circoviridae are large, almost the size of Poxviruses.
False, size is 17-22 nm
What type of symmetry does the family circoviridae have? Enveloped?
Spherical, icosohedral.
Non-enveloped
What type of DNA does Circoviridae contain?
Circular single-stranded DNA.
What DNA sense do circoviruses have? Gyroviruses?
Circoviruses- ambisense
Gyroviruses- Negative sense
What is significant about Chicken Infectious Anemia Virus structure compared to other viruses in Circoviridae?
12 trumpet like structures
Where do Circoviridae viruses replicate?
In the nucleus of a cell (actively dividing cell)
What is the most common route of transmission of Post-Weaning Multisystemic Wasting Syndrome in pigs?
Fecal-oral
Can PMWS be vertically transmitted?
yes, transplacentally
Is Circoviridae stable in the environment?
yes
Concerning PMWS where would you see “botryoid bodies” during histology?
Macrophages
what pathogenesis is consistently seen in the blood of pigs infected with PMWS?
Lymphopenia- however this loss of lymphocytes is not well understood
What happens if transplacental infection with PMWS occurs in the 1st or 2nd trimester?
Resorption or abortion of fetus
Clinical Signs of PMWS
Lethargy Progressive weight loss Cough Dyspnoea Stunted growth Lymphadenopathy Diarrhea Skin Discoloration Congenital tremors Possibly icterus
A pig with PMWS is also infected with Mycoplasma hyopneumoniae. What disease would you expect to see?
Chronic bronchopneumonia
When would you give the following PCV-1 or PCV-2 vaccinations:
1st piglet dose
2nd piglet dose
Sow dose
1st- 3 weeks
2nd- 6weeks
Sow- 2-5weeks antepartum
What disease, other than PMWS, is associated with PCV-2?
Porcine Dermatitis and Nephropathy Syndrome
PDNS
PDNS is reported in what age group of pigs?
Older piglets
Chicken Anemia Virus causes what disease in chickens?
Chicken infectious Anemia
What age group is CAV highly contagious to?
Chicks 2-4 wks old
How is CAV transmitted?
Shed in feces and dander- inhaled or oral exposure
vertically
Which cells is CAV replicated in causing anemia and immunosuppression?
hemocytoblasts
Tcells
What is the protein associated with CAV induced apoptosis of replicating cells?
Apoptin
Clinical signs of Chicken Infectious Anemia
Anorexia Lethargy Depression reduced weight gain Low PCV Watery blood with low clotting ability SubQ hemorrhages Skeletal hemorrhages
What happens to the thymus of chickens infected with CAV?
Atrophy
Concerning vaccination protocols for chickens, what other disease should be controlled due to the synergistic immunosuppressive factors?
Marek’s disease
