coronaviridae

Question 1

General characteristics:

Genetic Material

Enveloped?

Answer 1

ssRNA

Enveloped (photosensitive, unstable in envt but is stable in cold temperatures)

Question 2

important viruses in coronaviridae

Answer 2

bovine coronavirus

Transmissible gastroenteritis (pigs)

feline enteric coronavirus –> feline infectious peritonitis

infectious bronchitis (chickens)

Question 3

Bovine Coronavirus

1. types of dz virus causes
2. method of transmission
3. zoonotic?
4. does it change/recombine/mutate
5. distribution
6. diagnosis
7. differential diagnosis
8. control

Answer 3

1. calf diarrhea
2. persistent in host. the tropism is epithelial cells of respiratory and gi tract. interspecies transmission with a wildlife reservoir
3. YES ZOONOTIC

4.

5. all over
6. direct IFA of fecal sample or EM for crown shape. pcr
7. differerntial diagnosis: rotavirus (4-14 d) and coronavirus (4-30 d)
8. vaccinate pregnant animals with MLV that can cross placenta. give colostrum. biosecurity.

Question 4

Transmissible Gastroenteritis (TGE)

1. types of dz/signs
2. method of transmission
3. zoonotic?
4. does it change/recombine/mutate
5. distribution
6. diagnosis
7. differential diagnosis
8. control

Answer 4

1. in neonatal pigs. vomiting, diarrhea, anorexia and weight loss due to villus atrophy.
2. persistent in host resp and gi epithelial cells
3. not zoonotic
4. it mutates a lot bc RNA virus
5. not in usa. mostly in winter months bc stable in cold
6. IFA (for ag) of intestinal cells. VIrus isolation and RT-pcr
8. vaccinate sows three weeks before farrowing with attenuated vac.

Question 5

Feline Enteric Coronavirus (FeCoV)

1. types of dz virus causes
2. method of transmission
3. zoonotic?
4. does it change/recombine/mutate
5. distribution
6. diagnosis
7. differential diagnosis
8. control

Answer 5

1. mild enteric or respiratory dz
   - persistent infection
   - two serotypes: 1 is more common

2 is able to crossreact with canine coronavirus

• both are able to cause FIP
  2. fecal oral or contact. rarely spreads horizontally
  3. not zoonotic
  4. very prone to recombine. Quasispecies- each cat has own population of virus. Persistence in host. NOT reinfection
  5. 25% household cats are seropositive. 75% catteries are seropositive. infection occurs in utero or soon after maternal antibodies are gone
  6. no way to diffferentiate btwen FeCoV and FIP
  7. FeCoV and FIP
  8. control- vac available but is an intranasal temp sensitive vac that can actually cause antibody dependent enhancement and help virus get into cells.

Question 6

FIP

1. types of dz virus causes
2. method of transmission
3. zoonotic?
4. does it change/recombine/mutate
5. distribution
6. diagnosis
7. differential diagnosis
8. control

Answer 6

1. fatal young cat dz (3-18 mos). results in chronic fever, anorexia, weight loss, increased serum proteins, globulins, anemia, bilirubin
   - dry form- granulomas, cloudy eyes, neurological signs.
   - wet form- peritonitis, pleuritis (can switch from dry–>wet)
2. not spread from cat to cat. young cats dev in utero or after maternal abs gone. mutation of fecov occurs in individual cat and not every cat will dev FIP.
   - replicates in macrophages. worse with stress. immune mediated cell lysis
3. not zoonotic
4. derived from fecov mutation
5. catteries are at inc risk.
6. diagnosis based on serology with high globulins and proteins and degenerate white cells
7. differential diag: felv, cholioangiohepatitis, retrovirus infections
8. intranasal vac temp dep (cool) but only approved for 16 wks - too late bc infection occurs earlier. will test positive in future.

Question 7

infectious bronchitis

1. types of dz virus causes
2. method of transmission
3. zoonotic?
4. does it change/recombine/mutate
5. distribution
6. diagnosis
7. differential diagnosis
8. control

Answer 7

1. young chickens get respiratory distress and sneezing, decreased egg production, lesions. SARS?
2. oculonasal secretions
3. not zoonotic
6. virus isolation, ELISA, AGID, RT-PCR
7. infectious laryngotracheitis, newcastle
8. vaccination