circoviridae

Question 1

family circoviridae has two genus groups

Answer 1

circovirus and gyrovirus

Question 2

circovirus has three species

Answer 2

Psittacine beak and feather disease, Porcine circovirus type 1 ( non path), Porcine circovirus type 2 ( Post weaning multi systemic wasting syndrome (PMWS))

Question 3

gyrovirus has one species

Answer 3

chicken infectious anemia virus

Question 4

circoviridae general

Answer 4

small 17-22nm
circovirus=ambisense ss circular DNA
gyrovirus= circular ss negative sense DNA
chicken infectious anemia has 12 trumpet like structures

Question 5

circoviridae replication

Answer 5

occurs in actively dividing cells, DNA rep in nucleus during S phase of Interphase
virions stable at pH 3-9 and 30 min at 60 degrees celcius

Question 6

Post-weaning Multisystemic Wasting Syndrome (PMWS)

Answer 6

caused by porcine circovirus 2
pigs 4-6 weeks or post weaning 2-3 weeks
worldwide distribution
fecal oral transmission
virus in all secretions, can survive in stable and on fomites

Question 7

PMWS pathogenesis

Answer 7

replication not well understood
botyroid (grape-like) intra-cytoplasmic inclusion bodies in virus infected macrophages
targets cardiomyocytes, hepatocytes, and macrophages during fetal life and mainly monocytes in early post-natal life
lymphnode depletion in pigs, Loss of B and T cells

Question 8

PMWS transmission and clinical signs

Answer 8

transplacental in first and second trimesters
subclinical most common, lethargy ictherus, congenital tremors
can be co-infection with porcine parvovirus cause more sever disease (aborted fetus and mummies stillborn fetuses)
M. hyopneumonia co infection causes chronic bronchopneumonia

Question 9

PMWS diagnosis

Answer 9

blood, tonsils, lymph nodes, spleen ileum

characteristic histopath, PCR, serological assays

Question 10

PMWS vaccination

Answer 10

chimeric vaccines-use non path PCV-1 to express capsid of PCV-2
inactivated or baculovirus-expressed-PCV-2 inside capsid protein

Question 11

Porcine Dermatitis and Nephropathy Syndrome

Answer 11

associated with PCV2, sporadic, older pigs, skin lesions, vasculitis and glomerulonephritis all necrotizing

Question 12

gyrovirus

Answer 12

chicken infectious anemia

Question 13

chicken infectious anemia

Answer 13

chicken anemia virus, member of circoviridae
host-young chickens
transmission-feces and feather dander, inhalation, egg, stable in environment

Question 14

Chicken infectious anemia pathogenesis

Answer 14

hemocytoblasts in the bone marrow, precursor T cells in thymus and CD8 and CD4 in spleen, apoprotein induces apoptosis, immunosuppression and aplastic anemia, vulnerable to secondary bacterial and fungal infection, estrogen level increased will speed along replication

Question 15

Chicken infectious anemia clinical signs

Answer 15

anorexic, lethargic, depressed, pale, blood watery, slow clotting, PCV low, sub q hemorrhage, atrophy of thymus, apple carcass and bone marrow, atrophy of bursa

Question 16

chicken infectious anemia diagnosis

Answer 16

clinical signs, low PCV, trhombocytopenia, necropsy, ELISA, PCR, neutralization test

Question 17

Chicken infectious anemia vaccination

Answer 17

antibodies in breeders reduce transmission, the vaccine protects the progeny from vaccinated breeders by using maternal antibodies, injection, control of Mareks important since genetical similar