arteriviridae

Question 1

arteriviridae general

Answer 1

enveloped, spherical, linear + sense ss RNA, infectious RNA, frequently establish persistent infections, cytoplasmic replication,
ER budding off virions released by exocytosis

Question 2

equine arteritis

Answer 2

one serotype, equine host, present in most countries, occur through lateral spread, venereal transmission (natural or artificial breeding) , and horizontal transmission, respiratory route most common, stallion is reservoir,
mares always infected, transplacental transmission can occur

Question 3

equine arteritis path

Answer 3

macs and endothelial cells are site of replication, causes damage to blood vessels leading to generalized edema and hemmorhages, replication in semineferous tubules can cause infertility, cross of virus to fetus cases fetal death because of necrotizing myometritis and placental detachment

Question 4

equine arteritis clinical signs

Answer 4

adult horses- primary infection is asymptomatic, fever, depression, anorexia, limb edema, edema of prepuce, scrotum, mammary gland, urticaria
neonatal foals- interstitial pneumonia and enteritis

Question 5

repro clinical signs in horses

Answer 5

mare-abortion or congenital defects

stallion-short term sub fertility, not due to direct effect of virus because of increased intratesticular temperature

Question 6

Dx equine arteritis

Answer 6

necropsy for common lesions of edema, congestion, and hemorrhages of SQ tissue, lymph nodes and visceral organs

Question 7

arteritis control

Answer 7

vaccinate colts and noncarrier stallions, carrier stallions manages separately and bred only with seropositive mares

Question 8

porcine reproductive and respiratory syndrome (PRRS)

Answer 8

Swine mystery disease, blue ear disease, arterivirus, only infects wild and domestic pigs, aerosol, direct contact, infected semen, transplacental transmission
piglets may be born viremic and transmit infection up to 112 days after birth

Question 9

PRRS path

Answer 9

replication in macs in lungs and lymphoid tissues, lesions include lymph node enlargement and interstitial pneumonia, 2 phases-repro failure and respiratory disease post weaning

Question 10

repro failure PRRS

Answer 10

late term abortion, SMEDI, gross lesions in umbilical cords

Question 11

respiratory syndrome PRRS

Answer 11

severe resp distress, necrotizing interstitial pneumonia, fever, red discoloration of body, pericarditis

Question 12

PRRS control and diagnosis

Answer 12

Dx- ELISA

control- live attenuated and inactivated vaccines, control of PRRS by exclusion