Family Circoviridae

Question 1

genus within the family, 3 diseases within

Answer 1

circovirus

1. psittacine beak and feather disease virus
2. porcine circovirus type 1 (NON PATH)
3. porcine circovirus type 2 (Post weaning multisystemic wasting syndrome PMWS)

Question 2

SS or DS dna?
shape of DNA?
waht type of DNA

Answer 2

Circular, SS ambisense DNA

Question 3

where does virus rep occur
stable? temp and pH they can resist?

Answer 3

virus rep occurs in actively dividing cells

VERY stable, resists 60 deg. C for 30 min and pH 3-9

Question 4

post weaning multisystemic wasting syndrome (PMWS)
-caused by what virus
-host and most common age group

Answer 4

caused by porcine circovirus type 2
-pigs - most common at 4-6 weeks of age or 2-3 weeks post weaning

Question 5

PMWS
-transmission

Answer 5

fecal -oral trnamission is most common method, virus is found in ALL secretions (nasal, oral, urine), vertical transmission occurs (transplacental), virus can survive on fomites

Question 6

PMWS
-pathogenesis

Answer 6

characterized by individual to coalescing necrotic foci of granulomatous inflammation in lymph tissue, lungs, liver, kidney, heart and intestines with prominent “botryoid” grape like intra cytoplasmic inclusion bodies in virus infected macrophages

= lymphoid DEPLETION, loss of B and T cells, cause unknown

Question 7

PMWS
-differences in transplacental timing infections

Answer 7

infection during 1st and 2nd trimesters: fetal death and resorption or aborted fetus with severe cardiac congestion
3rd trimester: minimal effect on fetus

Question 8

PMWS
-CS

Answer 8

subclinical infection is MOST COMMON
-CS: lethargy, progressive weight loss, cough, slow growth, swollen LN, skin discoloration, diarrhea, tremors
-co infection with porcine parvovirus = causes more severe disease and more pronounced lesions

Question 9

PMWS
diagnosis
2 types of vax

Answer 9

-serological assay: AG not much value
-detection of PCV - 2 nucleic acids by PCR

1. chimeric vax: take gene for AG protein for PCP 2 and put into PCP 1 because it is nonpath. = get immunity for PCV 2
2. inactivated or baculovirus expressed vax: virus like particles that include capsid protein of PCV 2 are also avail.
   VAX sow 2 and 5 weeks antepartum

Question 10

porcine dermatitis and nephropathy syndrome (PDNS)
-associated with what virus?
-very common?
-what age group affected
-CS

Answer 10

assoc. with PCV 2
-sporadic! not as widespread as PMWS
-reported in older piglets
CS: necrotizing skin lesions, necrotizing vasculitis, necrotizing and fibrinous glomerulonephritis