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Flashcards in coronaviridae Deck (35):
1

coronaviridae 1 a /1 b

feline enteric coronavirus, canine coronavirus, transmissable gastroenteritis virus of swine, porcine respiratory coronvirus, porcine epidemic diarrhea virus 1 b

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2a

procine hemagglutiniating encephalomyelitis, mouse hepatitis virus, sialodacryoadenitis virus of rats, bovine coronavirus

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2b

SARS

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3

avian infectious bronchitis, turkey coronavirus, bluecomb virus

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coronaviridae general

enveloped, large club spikes, icosahedral internal core structure with helical nucleocapsid (coronavirus) or tightly could tubular nucleocapsid bent into donut shape (torovirus) single molecule of linear, positive sense, single stranded RNA
replication in cytoplasm and budding from ER released by exocytosis

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transmissable gastroenteritis in pigs (TGE)

highly infectious, vomitting dehydration, diarrhea, high mortality in pigs, other pigs susceptible OIE B list
TGE causative agent belongs to coronavirus
2 forms epidemic and endemic

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endemic TGE

when virus persists in a partially immune heard, due to concurrent porcine resp coronavirus infection; less sever and lower morbidity and mortality

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TGE transmission

TGE in USA
transmission-FO most likely

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epidemic form

when virus is first introduced into susceptible herd and is observed in the winter; rapid speed-high morbidity and mortality

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Path TGE

infects intestinal villa and causes atrophy and malabsorption or shows blunting and fusion of villi, both resulting in diarrhea

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Transmissable TGE

incubation 24-48hrs
onset sudden
signs= profuse diarrhea, vomiting, severe depression and dehydration, watery/yellow stool, feces may contain undigested milk, distended intestine. dilated stomach, bloated gut

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TGE Dx

necropsy and histopath, Fluorescence stain, immunohistochemistry, detection of nucleic acid by RT PCR

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TGE control

isolation of sows due to farrow, don't sell and purchase breeding stock, partial culling, biosecurity measures implemented, all in/all out management, complete depopulation and establishment of new herd, vaccination of pregnant sows and neonatal pigs

14

porcine epidemic diarrhea (PED)

coronavirus group 1b, clinical signs similar to TGE, fecal oral spread, acute outbreaks of diarrhea, vomiting with high morbidity and variable mortality

15

Porcine Hemagglutination encephalomyelitis ((vomiting and wasting disease in pigs) VWD)

if virus present then will bind to RBC.
aerosol contact-replication in nasal mucosa, replication in lungs, tonsils, small intestine, spread peripheral and central CNS replication in central CNS leads to acute encephalomyelitis
also leads to vomiting and malnutrition leaden to wasting

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VWD clinical findings of vomiting and wasting form

repeated retching and vomiting, rapid emaciation, neonatal pigs become dehydrated, cyanotic and comatose and die, anterior abdomen distended from impaired emptying and accumulation of gas

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VWD encephalomyelitic

non suppurative enceph.

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bovine coronavirus in calves

causes diarrhea 1 daya-3 mo of age, more common in winter months, fecal oral transmission, infects and replicates in villi and causes atrophy resulting in diarrhea (frequent major symptoms causing explosive outbreaks), other milder form of respiratory infection by aerosol causes tracheitis and rhinitis

19

bovine coronavirus treatment

commercial K99 vaccines using E.col, vaccinate healthy pregnant heifers, leads wot more protective antibodies triggering passive immunity in colostrum

20

winter dysentary in cows

common in mature lactating cows, young cattle may be infected but normally exhibit mild clinical signs, fecal oral transmission, sudden explosive diarrhea, green/black feces, dehydration, decline in milk production, some coughing

21

FIP

highly immune mediated disease of cats, triggered by systemic Feline coronavirus, enigmatic (poorly understood biologically) , transmission can be fecal oral or transplacental, can result in resistant, transient (mild diarrhea), or persistent carriers

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FIP hypotheses

either the cat contracts avirulent form or virulent form or the cat has both forms circulating at once

23

results of cell mediated response in FIP

strong response-> prevention of FIP
weak response Cell mediated with strong hummoral-> wet FIP, peritonitis, plueritis, vasculitis, ascites, glomerulonephritis, intermediate response-> dry form small granulomas, ocular lesions, CNS involvement

24

FIPV

replicate mostly in monocytes and macrophages, infection disseminated after activating macrophages, antibody dependent enhancement where the wet form is more infectious withe deja and vasculitis

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FIP wet form signs

distended abdome, diffuse peritonitis, ascites, pyogranulomatous foci on serosal surface, sebrinous pleuritis, thoracic effusion, pyogranulomatous omentum

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FIP dry form

granulomatous inflammation and enlarged mesenteric lymoh nodes, pyogranulomatous kidney, granulomatous meningoencephalitis, granulomatous uveitis, kertatic precipitates

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FIP Dx

Rivalta test-if drop disappears the neg
if drop stays then FIP + ; ELISA, IFA, but these won't differentiate between strains

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FIP prevention

Vaccine is intranasal, but not recommended

29

avian infectious bronchitis

common, highly contagious, acute, economically important, S protein is significant because variation leads to antigenic variation, some serotypes are called protoectotypes and have the ability to protect other serotypes , tropism in resp. but also enterotropic neprhotropic uterotropic and pro ventricular

30

IBV transmisson

aerosol, direct contact, contaminated wage, or food ; can come from coughing, feces, and egg surface, can cause decline in egg production

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IBV resp dZ

severe inflammation makes it hard to breath, causes depression, gasping, dyspnea

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IBV Nephritis

white irate deposits, visceral gout, irate also on heart, kidney, kidneys swollen, distended ureter, kidney stones

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IBV repro effects

soft shells, discolored eggs, albumen thin and watery, involuted flaccid ovarian follicles, stunting, dwarf embryo

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IBV control

live vaccines in broilers, Massachusetts has own vaccine,
inactivated vaccine for layers and breeders

35

toroviruses

bovine torovirus-cause gastroenteritis, donut shaped nucleocapsid, fecal oral transmission, causes diarrhea, infects epithelial cells of lower half of villi and colon and cecum