Virology Midterm Flashcards
What should NOT be done to samples where you want to detect the virus?
no fixatives, no freezing
What should NOT be done to samples where you want to detect the virus?
no fixatives, no freezing
What is the definition of a sensitive diagnostic test?
precentage of animals with dz that test positive
What is the definition of specificity in relation to diagnostic tests?
animals that test negative that are healthy
What diagnostic methods are indirect examination?
Cell culture, embryonated eggs, animals and serology
What is a seroconversion?
4 fold or more increase in titer of IgG or total antibody
What is the criteria for diagnosing re-infection?
1 fold or more increase in IgG or total antibody, absence or slight increase in IgM
What is hemagglutination inhibition?
virus specific Ab interfere with agglutinating RBCs
What are the viruses that hemagluttinate RBCs?
Pox, Parvo, Toga, Flavi, Orthomyxo, Paramyxo, Corona, Bunya, Rhabdo and Reo
What is the virus neutralization assay?
quantifies neutralizing Ab, confirms identity of virus
What does Tissue culture infective dose 50 (TCID50) measure?
virulence of virus
What does CPE stand for?
quantification of cytophathic effect
What term is used for frequency of disease in population in a specific period of time?
incidence
What term is used for frequency of a disease at a moment in time?
prevalence
What term is used for disease that has an insect vector involved and the virus replicates in the vector?
arboviral disease
Which virus has all the hosts remain as latent carriers?
herpes
What herpes virus is an exception to being species specific?
pseudorabies
Which pox virus is an exception to being species specific?
cowpox
How are most pox viruses transmitted?
vectors
Why is pox an exception to most enveloped viruses?
very resistant in the environment
Where are most clinical signs in pox virus?
skin
What diagnostic tests are used for pox?
not always needed, PCR or EM for confirmation
What do adeno viruses have that make them susceptible to disinfectants?
penton fibers
What are the clinical signs of adeno viruses?
mostly respiratory
also hepatitis, death and decline in egg production
What do the intranuclear inclusion bodies of adeno viruses form?
paracrystalline arrays of viral particles
How is papo virus transmitted?
direct contact (but naked)
Which virus forms a “string of pearls”?
circoviridae
How are circo viruses transmitted?
naked virions in the environment
What virus replicates in the nucleus of dividing cells only?
parvo
What are is the hallmark clinical sign of parvo viruses?
panleukopenia
Why is serology not useful in parvo viruses?
seroprevelance high in pigs
fatality of dz in cats and dogs
What enveloped virus does not need it’s envelope to be infective?
asfaviridae
What is the only virus in the asfaviridae family?
african swine fever
What are the reservoirs and vectors for african swine fever?
soft ticks
How is corona virus transmitted?
direct and indirect (although enveloped, moderately resistant in environment)
What types of clinical signs are seen with corona virus?
respiratory and GI but also CNS and repro
Which virus has a “pro” virus state where it inserts into host DNA?
retro virus
Which RNA virus is quite species specific?
retro virus
What are the two types of diseases retro viruses cause?
tumors
immunodeficiency
What diagnostic tests are used for retro viruses?
PCR and antibody ELISA
Which RNA virus is the host always a lifelong chronic or latent carrier?
retro virus
Which is the only retro virus that has a vaccine?
feline leukemia
Which viruses have fecal oral transmission?
reoviridae (reo and rota)
Which reoviridae member causes severe systemic disease?
orbivirus
What clinical sign does rotavirus produce?
diarrhea
What are the two important groups of flaviviridae?
pestivirus and flavivirus
What characterizes flaviviruses?
arbovirus and zoonotic
What does pesitiviruses produce in animals?
persistently infected immunotolerant animals (will be missed by serology)
What is the only genus of paramyxo viruses that cause severe systemic disease instead of just respiratory?
morbiliviruses
What are the 2 types of peplomers that make up orthomyxo capsid?
HA - viral receptor
NA - neuroaminidase
important for typing, diagnostics
Which orthomyxo virus does not transmit by direct contact?
avian influenza (can shed into water)
Which species is refractory to infection by foot and mouth dz?
horses
What clinical signs does picornivirdae produce in ruminants and swine?
vesicular mucosal lesions
Where else can picorna viruses cause clinical sides besides mucosa?
myocardium, liver, CNS
What tests are used commonly for picorna viruses?
ELISA and RT-PCR
What are the intracytoplasmic inclusion bodies called in rhabdoviridae?
negri bodies
How is rhabdoviridae transmitted?
varies between genus
How is bunyaviridae viruses transmitted?
arbovirus in ruminants
What clinical signs does arteriviridae cause?
respiratory dz and abortions
How is the enveloped arteriviridae virus transmitted?
directly and indirectly
sexual and vertically
Which RNA virus has a bi-segmented genome?
birnaviridae
What are the reservoirs of toga viruses?
birds
What are the dead end hosts of toga viruses?
horses and humans
What CS does toga cause?
neurologic dz with sequuela
Which RNA virus multiplies in the nucleus and leaves intranuclear inclusion bodies?
bornaviridae
Where is bornaviridae virus found? Why is it important?
Germany, zoonotic
What can distinguish between different prion?
monoclonal antibody - confirmational epitope
How is prion disease diagnosed?
histopathology, IHC, WB of brain, not until postmortem
