Virology week 1 Flashcards
t/f epizootic diseases exceed the panzootic baseline?
F they exceed the enzootic (endemic) baseline
what are the three parameters of defining incidence in acute diseases?
S/P I/P C/I
S=susceptible population
I=those infected
C=those cases/diseased
What is the difference between prospective studies and retrospective studies? two main differences
Prospective- very expensive, can require a lot of subjects
retrospective- cost-effective, limited subjects needed
Direct contact is mostly associated with which type of virus? (enveloped or nonenveloped)
enveloped. this is because they have a hard time surviving in the environment
What is the main difference between arbo- biological vectors and mechanical vectors?
viruses replicate in the biological vectors and are more efficient compared to mechanical (no replication in these vectors)
What is a classical zoonotic viral disease? why?
rabies. transmissible from animals to humans
which modes of transmission are preventable and caused by veterinarians?
latrogenic and nosocomial with nosocomial being directly from the hosptial
what is a latent virus and what does it mean if recrudescence occurs?
latent viruses incorporate into the genome. think herpes alpha in the ganglia. and, during recrudescence, stress causes the disease to flair up a new immune response will occur
2 important routes of virus shedding?
respiratory secretions and feces
t/f all viruses shed?
f CNS and retroviruses do not shed
What are the 7 stages of the virus replication cycle?
attachment - penetration - uncoating - macromolecular synthesis - replication - assembly of virions - release
How do VAPs (viral attachment proteins) vary on enveloped and nonenveloped viruses?
nonenveloped have VAPs that are a part of the capsid.
enveloped viruses VAPs are glycoproteins on the envelope
t/f if the host does not have a receptor for that virus then it will not get infected
t specific receptors for those viruses must be present for recognition/infection
3 ways viruses penetrate the cell
translocation- nonenveloped
endocytosis- enveloped. taken into a vesicle
fusion- enveloped. lipid bilayers fuse.
why does uncoating have to occur?
releases nucleic acid genome into cell. it can now use cellular metabolism to synthesize viral proteins
Where do all DNA viruses replicate? what is the exception?
Nucleus. exception is poxvirus
all RNA viruses replicate in the cytoplasm except for?
coronaviruses, retroviruses, and orthomyxoviruses
What is Cytopathic effect? example?
morphological changes that a cell goes through after interacting with a virus. rounding, lysis, syncytia.
what general type of viruses can survive in the GI tract and infect there?
nonenveloped viruses because they can survive harsh environments.
viremia?
virus travels through blood. most efficient systematic spread
What routes of viral spread are inefficient?
neural- too slow
lymphatic- inefficient
local- few cells effected
What two things cause CPE (cytopathic effect) of cells?
direct pathological injury
side effect from the cells altered metabolism after their machinery was hijacked to make viruses
what is the infectious agent in most viruses?
nucleic acids
T/F bacteria and viruses are sensitive to antibiotics
just bacteria not viruses
