Virology (Midterm Ii, Set I)

Front 1

What is the genome of Parvoviridae?

Back 1

ssDNA

Front 2

What is the morphology of Parvoviridae?

Back 2

non-enveloped

icosohedral

Front 3

What will be the CPE from parvovirus infection?

Back 3

cytolysis (b/c it's non-enveloped and has to break out)

nuclear inclusion bodies (b/c it's a DNA virus)

Front 4

What type of tissue does parvovirus infect?

Back 4

Cells in S phase:

intestinal crypt cells

lymphoid cells (bone marrow)

CNS (in growing animals)

Front 5

What's the difference between feline parvovirus and canine parvovirus?

Back 5

Tissue tropism

In kittens see cerebellar hypoplasia

In puppies see myocarditis (and pulmonary edema)

Front 6

What is similar between porcine parvovirus and canine parvovirus?

Back 6

Same family = genome, replication, morphology

Front 7

Is parvo environmentally stable or unstable? Why?

Back 7

non-enveloped = very stable in environment

pH resistant (important for passage through stomach to colonize intestine)

resistant to solvents and high temperatures

Front 8

How does parvovirus enter host cells?

Back 8

virus capsid protein VP2 binds to host cell surface receptors

Front 9

Will parvovirus cause immunosuppression in young animals? old animals?

Back 9

both!

immunosuppression (panleukopenia) from replication in lymhpoid cells occurs in animals of any age

Front 10

Don't confuse feline panleukopenia and feline leukemia virus! What family are each virus in?

Back 10

FPV = Feline Panleukopenia virus = parvoviridae

FeLV = Feline Leukemia virus = oncovirinae (retrovirus)

Front 11

How is FPV transmitted?

Back 11

all the ways

shed in all body secretions

may remain viable in environment for years

oral-fecal transmission common

may have arthropod vectors

vertical transmission through placenta

Front 12

What is the clinical presentation of FPV?

Back 12

Fever for the first 24hrs (initial infection) and again 3-4 days later (systemic infection)

Diarrhea and vomiting = dehydration

Severe leukopenia (after 3-4 days when virus reaches bone marrow)

** cerebellar hypoplasia in kittens

** acute death can occur in 12 hours

Front 13

What will you see in an H&E stain in the brains of kittens infected with FPV?

Back 13

inflammation, infiltration of lymphocytes, necrosis, tissue damage, inclusion bodies in neuron nuclei

Front 14

What type of cells are infected by FPV in older cats?

Back 14

intestinal crypts and leukocytes (bone marrow)

Front 15

What is the pathology of FPV?

Back 15

widespread destruction of leukocytes (lymphocytes, neutrophils, monocytes, platelets, all destroyed)

extensive necrosis of intestinal crypts and collapse of lamina propria

Front 16

How is FPV diagnosed?

Back 16

clinical signs

hematological examination (WBCs)

Snap test (chromatographic test strip) detects antigen)

serologic testing (detects antibody)

EM

PCR

Front 17

What is the most common pathology in puppies infected with CPV?

Back 17

enteritis, diarrhea (+/- blood)

vomiting

leukopenia (in about 45% of cases)

fever (24%)

prone to secondary infection

Front 18

There are several subtypes of CPV. What is the difference?

Back 18

CPV1 = mild diarrhea

CPV2(a,b) = three distinct forms of disease (generalized neonatal disease, enteritis/leukopenia, myocarditis)

CPVc = enteritis

Front 19

In a puppy with enteritis, what are the important viral differentials?

Back 19

parvovirus

distemper virus

coronavirus

rotavirus

Front 20

Why are CPV vaccines not administered until a puppy is 6-8 weeks old?

Back 20

maternal antibodies interfere with vaccine

Front 21

What is the most common and important cause of infectious infertility in swine?

Back 21

Porcine parvovirus disease (PPV)

(usually multiplies in GI tract without causing disease)

Front 22

The pathology of parvovirus is shaped by their dependence on _______________ for replication

Back 22

host cellular functions

Front 23

Does parvovirus have narrow or broad cell tropism?

Back 23

broad, pretty much any cell in S phase

But since there aren't as many of these cells in adults, typically targets intestinal epithelium and leukocytes

Front 24

What is the genome of coronavirus?

Back 24

+ssRNA

LARGEST RNA VIRUS

Front 25

What is the morphology of coronavirus?

Back 25

enveloped

(more susceptible in environment, easily killed with disinfectants)

Front 26

What type of tissue damage is associated with FIP?

Back 26

immune mediated tissue damage

Front 27

How do pyogranulomas form during an FIP infection?

Back 27

accumulation of antibody-antigen complexes stimulates complement cascade and leads to chronic inflammation

Front 28

What's the difference between feline coronavirus and FIP?

Back 28

tissue tropism. A mutation allows FIP to infect macrophages

Front 29

What is common between feline and canine coronavirus?

Back 29

genome, replication, morphology

Front 30

Is the coronavirus genome infectious by itself?

Back 30

YES!

Front 31

What viral protein is the major antigen for coronavirus?

Back 31

spike protein

Front 32

What is the common feature between arteriviruses and coronaviruses?

Back 32

Both in the order Nidovirales, nested viruses

same order = same genome type and replication, different morphology and different host/tissue specificity

Front 33

How are coronaviruses classified?

Back 33

Group 1 (alpha)

Group 2 (beta)

Group 3 (gamma)

Front 34

What proteins determine the morphology of coronavirus?

Back 34

S = spike glycoprotein

E = envelope protein

M = membrane protein

N = N-phosphoprotein, non-structural protein

Front 35

What kind of pathology do coronavirus infections typically cause?

Back 35

respiratory infections (common)

enteric infections

Front 36

How is coronavirus transmitted?

Back 36

aerosols of respiratory secretions

oral-fecal transmission

Front 37

What cells in the digestive tract are targeted by coronavirus?

Back 37

surface epithelial cells of intestinal villi

remember that coronavirus is an RNA virus, so it doesn't need cells to be in S phase for replication (unlike parvovirus, which targeted intestinal crypt cells)

Front 38

FeCV (feline enteric coronavirus) has 2 serotypes. What is the difference between them?

Back 38

Serotype 1 is the most common (70-95% of isolates)

Serotype 2 is a recombinant with canine coronavirus

Front 39

What kind of disease is seen with FeCV?

Back 39

mild enteric disease

respiratory disease

Front 40

What is the importance of persistent infections with FeCV?

Back 40

premunition = cats infected with FECV will be protected from other FECV

Front 41

There is an average of three base pair changes every time a coronavirus replicates. why?

Back 41

poor proofreading and high error rate of RDRP

about 1 mistake every 10,000 bps

with a 30Kbp genome = 3bp changes

Front 42

How does an animal get FIP?

Back 42

infected with FeCV, which mutates in the host (5% of FeCV infections). This mutation typically occurs in animals that are stress (pregnancy is a common example)

Front 43

What is the difference between FIP and FeCV?

Back 43

FIP virus has the ability to replicate in macrophages (especially peritoneal macrophages), monocytes, and other leukocytes

Front 44

What are the two different clinical forms of FIP?

Back 44

Wet and dry

Front 45

What is wet FIP?

Back 45

infection of monocytes = release of cytokines = leakage of fluid into body cavities

peritoneal and pleural effusion

ascities

more severe form of disease

Front 46

What is dry FIP?

Back 46

immune complexes + inflammation = pyogranulomas and necrosis in multiple organs (abdomen, thorax, CNS, eyes)

fibrosis of liver, mesenteric lymph nodes, kidneys

CNS = perivascular cuffing

less acute

Front 47

In FIP one form may progress into the other. Which typically comes first?

Back 47

dry FIP --> wet FIP

Front 48

What is the involvement of the immune system in FIP?

Back 48

humoral immunity is not protective

adaptive immunity is actually what causes the pathogenesis.

antibodies actually enhance virus ability to enter target cells

immune complex disease

Front 49

How is FIP diagnosed?

Back 49

Mostly based on clinical signs

Can do serology against FeCV

histopathology at necropsy

cytology of blood sample

Front 50

If you do a FeCV serology test on a cat and the serology comes back <100, what does this mean?

Back 50

FeCV serology <100 = less chance of developing FIP, >100, greater chance of getting FIP

Front 51

How should you control/prevent FIP infection in cats?

Back 51

Don't vaccinate! Will stimulate immune system, and that's exactly what you don't want

Early weaning and separation of kittens

(if mom is actively shedding. maternal antibodies should protect kittens until 6-8 wks of age. Remove them from infected mom around 5 wks of age)

Front 52

What is winter dysentery?

Back 52

bovine coronavirus enteritis

acute, highly contagious GI disorder of cattle

Front 53

What are the clinical features of bovine coronavirus enteritis?

Back 53

explosive onset

dark, hemorrhagic diarrhea

dramatic drop in milk production

Front 54

What are the 3 important porcine coronaviruses?

Back 54

Porcine hemagglutinating encephalomyelitis (PHE)

Porcine transmissible gastro-enteritis (TGE)

Porcine epidemic diarrhea (PED)

Front 55

What are the two forms of Porcine hemagglutinating encephalomyelitis (PHE)?

Back 55

Acute encephalomyelitis (HEV)

CNS effects, very high mortality

Vomiting and wasting disease (VWD)

enteric effects, fever, vomitting, constipation, emaciation, occasional nervous involvement. high mortality

Front 56

A 5 day old piglet contracts Porcine hemagglutinating encephalomyelitis. What form will it present with?

Back 56

Acute encephalomyelitis

<7 days old

Vomiting and wasting disease

<4 weeks old

Front 57

Which form of Porcine hemagglutinating encephalomyelitis is more lethal?

Back 57

Both HEV and VWD have high mortality

HEV: up to %100 of piglets in affected litters die in 1-3 days

VWD: high mortality, survivors are often runts

Front 58

Which disease is more likely to affect older animals,

porcine hemagglutinating encephalomyelitis, or porcine transmissible gastro-enteritis?

Back 58

TGE

Front 59

You evaluate a piglet who's stomach and small intestine are distended with curdled milk. What disease do you suspect?

Back 59

porcine transmissible gastro-enteritis

Front 60

What are important viral differentials to consider when evaluating an animal for possible porcine transmissible gastro-enteritis?

Back 60

hemagglutinating encephalomyelitis (VWD)

classical swine fever

porcine rotavirus

swine dysentery

Front 61

New porcine coronaviruses are constantly evolving. What is changing about the virus?

Back 61

the spike glycoprotein

Front 62

Does FIP have the same genome and morphology as FCoV (FeCV)?

Back 62

Yes

Front 63

Does FIP have the same tissue tropism as FCoV?

Back 63

No

FIP = monocytes and macrophages

FCoV = epithelial cells

Front 64

What is the cause of pyogranulomas and necrosis of multiple organs in FIP+ cats?

Back 64

the dry (non-effusive) form of FIP

Front 65

What is the genome of adenovirus?

Back 65

dsDNA

Front 66

What is the morphology of adenovirus?

Back 66

non-enveloped

icosahedral

Front 67

What is the cell-tropism of adenovirus?

Back 67

pantropic

particularly epithelial cells

Front 68

Where in the cell does adenovirus replicate?

Back 68

nucleus (DNA virus!)

Front 69

How does adenovirus leave the host cell? What implication does this have for the pathology of the virus?

Back 69

cytolysis

necrosis in infected tissues

Front 70

adenoviruses have three classes of genes that are sequentially expressed. What are they?

Back 70

Immediate early genes

Early genes

Late genes

Front 71

Canine adenovirus type 1 is characterized by two different forms. What are they?

Back 71

Hepatic form (hepatocellular destruction)

Immune complex form (blue eye)

Front 72

What age of animals is most commonly infected with CAV-1?

Back 72

puppies

may see peracute death with no signs

death within 3-4 hrs of signs

infection is rare in older animals

Front 73

what symptoms are seen in dogs with CAV-1

Back 73

fever, depression, anorexia, vomitting, diarrhea, pale mucous membranes, petechiation of gums, jaundice, blue eye

Front 74

How does blue eye develop in dogs with CAV-1?

Back 74

antibody to CAV-1 passes into aqueous humor of eye

immune complexes of CAV-1 antibody and antigen activate complement

MAC releases proteases, collagenases, elastases, and oxygen radicals

---> corneal edema and opacity

Front 75

What is the difference between CAV-1 and CAV-2?

Back 75

tissue tropism. CAV-2 does not cause hepatitis, has much lower mortality

Front 76

Why vaccinate for CAV-2 if it doesn't cause severe disease?

Back 76

CAV-2 vaccine give cross-protection for CAV-1

Front 77

You are doing a necropsy on a puppy and find nuclear inclusion bodies in the liver. What virus should be at the top of your differentials list?

Back 77

CAV-1

Front 78

What is the morphology of calicivirus?

Back 78

non-enveloped, icosahedral

Front 79

What is the genome of calicivirus?

Back 79

+ssRNA

genome is infectious!

Front 80

What symptoms are typically seen with feline calicivirus?

Back 80

upper respiratory tract infection = sneezing, nasal discharge, runny eyes, cough, oral or nasal ulcers, sniffles, fever

Front 81

How is calicivirus transmitted?

Back 81

saliva, oral and nasal discharge, feces

Front 82

What is VS-FCV?

Back 82

virulent strain feline calicivirus

change in tissue tropism --> systemic symptoms

edema, cellulitis around joints, jaundice, dysphonia

High mortality (up to 50%)