Virology Midterm

Question 1

What should NOT be done to samples where you want to detect the virus?

Answer 1

no fixatives, no freezing

Question 2

What should NOT be done to samples where you want to detect the virus?

Answer 2

no fixatives, no freezing

Question 3

What is the definition of a sensitive diagnostic test?

Answer 3

precentage of animals with dz that test positive

Question 4

What is the definition of specificity in relation to diagnostic tests?

Answer 4

animals that test negative that are healthy

Question 5

What diagnostic methods are indirect examination?

Answer 5

Cell culture, embryonated eggs, animals and serology

Question 6

What is a seroconversion?

Answer 6

4 fold or more increase in titer of IgG or total antibody

Question 7

What is the criteria for diagnosing re-infection?

Answer 7

1 fold or more increase in IgG or total antibody, absence or slight increase in IgM

Question 8

What is hemagglutination inhibition?

Answer 8

virus specific Ab interfere with agglutinating RBCs

Question 9

What are the viruses that hemagluttinate RBCs?

Answer 9

Pox, Parvo, Toga, Flavi, Orthomyxo, Paramyxo, Corona, Bunya, Rhabdo and Reo

Question 10

What is the virus neutralization assay?

Answer 10

quantifies neutralizing Ab, confirms identity of virus

Question 11

What does Tissue culture infective dose 50 (TCID50) measure?

Answer 11

virulence of virus

Question 12

What does CPE stand for?

Answer 12

quantification of cytophathic effect

Question 13

What term is used for frequency of disease in population in a specific period of time?

Answer 13

incidence

Question 14

What term is used for frequency of a disease at a moment in time?

Answer 14

prevalence

Question 15

What term is used for disease that has an insect vector involved and the virus replicates in the vector?

Answer 15

arboviral disease

Question 16

Which virus has all the hosts remain as latent carriers?

Answer 16

herpes

Question 17

What herpes virus is an exception to being species specific?

Answer 17

pseudorabies

Question 18

Which pox virus is an exception to being species specific?

Answer 18

cowpox

Question 19

How are most pox viruses transmitted?

Answer 19

vectors

Question 20

Why is pox an exception to most enveloped viruses?

Answer 20

very resistant in the environment

Question 21

Where are most clinical signs in pox virus?

Answer 21

skin

Question 22

What diagnostic tests are used for pox?

Answer 22

not always needed, PCR or EM for confirmation

Question 23

What do adeno viruses have that make them susceptible to disinfectants?

Answer 23

penton fibers

Question 24

What are the clinical signs of adeno viruses?

Answer 24

mostly respiratory

also hepatitis, death and decline in egg production

Question 25

What do the intranuclear inclusion bodies of adeno viruses form?

Answer 25

paracrystalline arrays of viral particles

Question 26

How is papo virus transmitted?

Answer 26

direct contact (but naked)

Question 27

Which virus forms a "string of pearls"?

Answer 27

circoviridae

Question 28

How are circo viruses transmitted?

Answer 28

naked virions in the environment

Question 29

What virus replicates in the nucleus of dividing cells only?

Answer 29

parvo

Question 30

What are is the hallmark clinical sign of parvo viruses?

Answer 30

panleukopenia

Question 31

Why is serology not useful in parvo viruses?

Answer 31

seroprevelance high in pigs | fatality of dz in cats and dogs

Question 32

What enveloped virus does not need it's envelope to be infective?

Answer 32

asfaviridae

Question 33

What is the only virus in the asfaviridae family?

Answer 33

african swine fever

Question 34

What are the reservoirs and vectors for african swine fever?

Answer 34

soft ticks

Question 35

How is corona virus transmitted?

Answer 35

direct and indirect (although enveloped, moderately resistant in environment)

Question 36

What types of clinical signs are seen with corona virus?

Answer 36

respiratory and GI but also CNS and repro

Question 37

Which virus has a "pro" virus state where it inserts into host DNA?

Answer 37

retro virus

Question 38

Which RNA virus is quite species specific?

Answer 38

retro virus

Question 39

What are the two types of diseases retro viruses cause?

Answer 39

tumors | immunodeficiency

Question 40

What diagnostic tests are used for retro viruses?

Answer 40

PCR and antibody ELISA

Question 41

Which RNA virus is the host always a lifelong chronic or latent carrier?

Answer 41

retro virus

Question 42

Which is the only retro virus that has a vaccine?

Answer 42

feline leukemia

Question 43

Which viruses have fecal oral transmission?

Answer 43

reoviridae (reo and rota)

Question 44

Which reoviridae member causes severe systemic disease?

Answer 44

orbivirus

Question 45

What clinical sign does rotavirus produce?

Answer 45

diarrhea

Question 46

What are the two important groups of flaviviridae?

Answer 46

pestivirus and flavivirus

Question 47

What characterizes flaviviruses?

Answer 47

arbovirus and zoonotic

Question 48

What does pesitiviruses produce in animals?

Answer 48

persistently infected immunotolerant animals (will be missed by serology)

Question 49

What is the only genus of paramyxo viruses that cause severe systemic disease instead of just respiratory?

Answer 49

morbiliviruses

Question 50

What are the 2 types of peplomers that make up orthomyxo capsid?

Answer 50

HA - viral receptor NA - neuroaminidase important for typing, diagnostics

Question 51

Which orthomyxo virus does not transmit by direct contact?

Answer 51

avian influenza (can shed into water)

Question 52

Which species is refractory to infection by foot and mouth dz?

Answer 52

horses

Question 53

What clinical signs does picornivirdae produce in ruminants and swine?

Answer 53

vesicular mucosal lesions

Question 54

Where else can picorna viruses cause clinical sides besides mucosa?

Answer 54

myocardium, liver, CNS

Question 55

What tests are used commonly for picorna viruses?

Answer 55

ELISA and RT-PCR

Question 56

What are the intracytoplasmic inclusion bodies called in rhabdoviridae?

Answer 56

negri bodies

Question 57

How is rhabdoviridae transmitted?

Answer 57

varies between genus

Question 58

How is bunyaviridae viruses transmitted?

Answer 58

arbovirus in ruminants

Question 59

What clinical signs does arteriviridae cause?

Answer 59

respiratory dz and abortions

Question 60

How is the enveloped arteriviridae virus transmitted?

Answer 60

directly and indirectly | sexual and vertically

Question 61

Which RNA virus has a bi-segmented genome?

Answer 61

birnaviridae

Question 62

What are the reservoirs of toga viruses?

Answer 62

birds

Question 63

What are the dead end hosts of toga viruses?

Answer 63

horses and humans

Question 64

What CS does toga cause?

Answer 64

neurologic dz with sequuela

Question 65

Which RNA virus multiplies in the nucleus and leaves intranuclear inclusion bodies?

Answer 65

bornaviridae

Question 66

Where is bornaviridae virus found? Why is it important?

Answer 66

Germany, zoonotic

Question 67

What can distinguish between different prion?

Answer 67

monoclonal antibody - confirmational epitope

Question 68

How is prion disease diagnosed?

Answer 68

histopathology, IHC, WB of brain, not until postmortem