Exam 1: introduction, pathogenesis, diagnosis, vaccination Flashcards
(139 cards)
1
Q
Viruses acquire new host range via _____________ of viral genes
A
mutation
2
Q
infection + disease in new host species -> ________ host range
A
increased
3
Q
change in viral ____________ or _________ have the ability to spread efficiently between new individuals
A
receptor or proteins
4
Q
infection of new _________ ________
Ex: mutations in feline enteric corona virus -> replication in macrophages -> feline infectious peritonitis
A
cell types
5
Q
________ effects upon infected cells Ex: noncytopathic BVDV -> cytopathic BVDV -> mucosal disease
A
different
6
Q
____________ viral replication -> ___________ severity of disease
Ex: higher affinity of viral spike to ACE2R in Delta SARs varian
A
increased viral replication -> increased severity of disease
7
Q
T/F - Mutation does not always = more severe disease
Ex: Parvovirus 2a vs 2b vs 2
A
true
8
Q
responsible for distinct strains of many viruses; used in epidemiological studies to track virus spread / determine host
A
antigenic drift
9
Q
knowledge of viral ____________ is required for diagnosis, management, and prevention of viral disease
A
pathogenesis
10
Q
in this disease, vaccinated puppies may get the disease, as maternal antibodies interfere with development to the immune response to the vaccine – need to vaccinate every 2 weeks
A
canine parvovirus
11
Q
best test to differentiate between FIPV and feline enteric coronavirus
A
immunocytochemistry
12
Q
replicate in nucleus of cell
A
DNA viruses
13
Q
replicate in cytoplasm of the cell, high rate of mutation
A
RNA viruses
14
Q
replicate in nucleus, integrated into host DNA as a provirus
A
retroviruses
15
Q
an infectious, obligate intracellular parasites; hijack host cellular processes for replication & synthesis of viral components
A
virus
16
Q
vehicles for viral transmission
A
virions
17
Q
resistant to drying, heat, action of detergents, acid, and proteases
A
capsid
18
Q
___________ transmission vital for long-term survival in the environment, retained infectivity on surfaces
A
fomite
19
Q
_________________ viruses released via lysis of infected cell
A
non-enveloped
20
Q
component sensitive to heat, drying, detergents, acid; must stay dry to be transmitted to new host via droplets, secretions, feces
A
envelope
21
Q
T/F - Viruses with envelope do survive as long as non-enveloped viruses
A
false
22
Q
the process by which the envelope is acquired from the host cell membrane - virus therefore does not need to kill cells to spread
A
budding
23
Q
nuclear or cytoplasmic aggregates of viral substances, typically capsid protein; represent sites of viral multiplication
Ex: found in bronchiolar epithelial cells w canine distemper virus
A
inclusion bodies
24
Q
cell membrane is punctured, made to further connect with the unfolding viral envelope (i.e. herpesvirus, retroviruses, influenza)
A
cell membrane fusion / hemifusion
25
host cell takes in viral particle through receptor-mediated endocytosis OR phagocytosis (i.e. parvovirus)
endocytosis
26
injection of viral genome into host cytoplasm through creation of a pore in host membrane, mediated by pore-forming peptide (i.e. poliovirus)
Pore mediated penetration
27
study of infection and spread of viruses in the animal, and the mechanism by which disease is produced
pathogenesis
28
virus capable of inducing disease or lesions
pathogenic
29
measure of the ability of a virus to produce disease in the host; important in determining outcomes of infection
Ex: modified live virus < wild-type virus
virulence
30
T/F - Some infectious animals replicate and shed virus without clinical disease
true
31
sources of viral infections include:
a) infected animals
b) persistently-infected animals
c) animal products
d) environment
e) reservoir hosts
all of the above
32
most important route of transmission for most viruses -- direct contact, indirect contact, or vectors
horizontal
33
transmission between cohabitating animals (i.e. respiratory aerosol droplets)
direct contact
34
virus transmitted from parent to offspring (i.e. germplasm, eggs, placenta, milk)
vertical transmission
35
genetic material of an organism that may be transmitted from one generation to another
germplasm
36
dependent on titer of virus, distance between animals, air movement, droplet size, immunity to virus
respiratory transmission
37
Higher the titer = ________ the transmissibility
higher
38
Smaller distance between animals = ________ transmissibility
higher
39
Less air flow / ventilation = __________ transmissibility
higher
40
normal, immune fetus may result if infected in late pregnancy when fetus is immunologically competent
placental transmission
41
direct cell _________ -> loss of organ function
Ex: canine parvovirus: direct damage of crypt epithelium in SI -> failure to renew enterocytes -> blunting of villi + diarrhea
damage
42
cell ____________ -> tumor production + loss of organ function
Ex: Bovine leukemia virus lymphosarcoma
transformation
43
____________ cells which target the virus cause destruction of cells in its vicinity (Ex: Distemper, FIPV)
inflammatory
44
occurs via destruction of lymphocytes and macrophages
immunosuppression
45
disease in which antigen/antibody complexes accumulate in the basement membrane of renal glomeruli, arteries, or choroid plexus (Ex: Equine Infectious Anemia)
immune-complex
46
severity of disease is dictated by (3)
location, function, regeneration
47
T/F - skin, liver have capacity to regenerate & require extensive damage to cause disease, whereas neurons cannot regenerate and little damage causes severe disease
true
48
entry, replication, lesions, shedding occur within same organ system (i.e. influenza virus)
localized infection
49
spread to other systems upon entry, shedding in several secretions and excretions (i.e. distemper)
systemic infection
50
viral spread via lymphatics to regional lymph nodes
primary amplification
51
virus enters bloodstream -> _________ ________ -> no clinical signs
primary viremia
52
dissemination into central organs such as the liver, spleen, bone marrow, and vascular endothelium -> __________ ___________ -> clinical signs such as fever/malaise
secondary viremia
53
____________ into sites of shedding & primary lesions -> characteristic clinical signs, damage
dissemination
54
viral ________ and __________ occur before and during fever / clinical signs -- take diagnostic samples early, or wait until post-infection
replication and shedding
55
recovery from viral infections occurs via _____________ of susceptible cell populations
depletion
56
immune responses occur specifically via ________ and ______________ responses
antibody and cell-mediated cytotoxic
57
study of frequency and distribution of viral diseases in a population
viral epidemiology
58
prohibition or restriction on the movement or importation of animals / animal products from areas in which disease occurs (for imports, epidemics, biosecurity)
quarantine
59
restricts sources of infection by reducing the risk of exposure of domestic animals to reservoir hosts – includes housing livestock, fencing pastures, removal / vaccination of wildlife
wildlife control
60
intended to reduce the risk of spread of infection by insect vectors – includes insect proofing, insecticides, larvicides, adulticides
vector control
61
associated with presence/absence of host cell receptors on target cells, transcription factors, DNA replication enzymes, proteases
susceptibility
62
animals with defects in _________ _________ have higher susceptibility to viral infections
cell-mediated immunity
63
inhibit viral replication & kill viral-infected cells (3)
interferon, NK cells, macrophages
64
cell-mediated response occurs within________ , antibody production occurs within __________
10 days, 2 weeks
65
antibody production / CMI occurs __________ in higher frequencies with vaccine protection
faster
66
important in preventing initial entry of viruses, decrease initial load of virus in blood
antibodies
67
important in recovery from established viral infection, preventing further viral replication & clearance from host
cell-mediated immunity
68
may be related to maturation of immune system or stage of differentiation of target cells
Ex: parvovirus – infects cardiomyocytes in puppies 3w or less
Ex: feline panleukopenia – infects neurons in cerebellum in kittens in-utero up to 4 weeks of age
age
69
elevated body temp inhibits replication of many viruses, enhances host inflammatory reaction, aiding in viral clearance
fever
70
surface barriers include (3)
skin, intestinal enzymes, mucus
71
viruses __________ immune responses via:
a) induction of immunologic tolerance at a young age (i.e. BVDV)
b) infection of cells in immune-privileged sites
c) non-neutralizing antibodies
d) integration of viral genome into host chromosomal DNA
e) infection of lymphocytes & macrophages
f) inhibition of MHC function
avoid
72
down-regulation of viral protein expression // intracellular localization hides viral proteins
i.e. alpha herpes virus – sensory ganglion neuron latently infected, no viral protein expression
latency
73
viruses evade T cell-response via infection of cells lacking
MHCI
74
mutation of viral genes responsible for large number of serologically distinct strains of viruses; subtle changes directed by requirement to retain function & escape detection by existing antibodies
antigenic drift
75
viral genomic segments combine / reassort, producing highly pathogenic viruses; responsible for most severe influenza epidemics
antigenic shift
76
occurs when viral antigen persists, continued immune response at the site of viral infection results in extensive damage to surrounding tissue via the bystander effect (i.e. canine distemper, feline infectious peritonitis)
virus induced immune mediated inflammatory disease
77
antiviral antibody interacts with virus in the fluid phase, resulting in formation of virus-antibody immune complexes continuous trapping within renal glomeruli, arteries, choroid plexus glomerulonephritis, arteritis, choroiditis (i.e. equine infectious anemia)
immune-complex disease
78
often occurs as some viruses destroy lymphocytes, predisposing the host to develop opportunistic infection (i.e. feline immunodeficiency)
immunosuppression
79
detection of viral antigens/proteins via
ELISA/immunocytochemistry
80
detection of viral nucleic acids via
PCR
81
detection of antibodies to virus via
serology
82
All are _____________ & will give a negative test if the target virus is not present, even if other viruses are
virus-specific
83
________ result confirms presence of a specific virus OR antibody to a virus; indicates chronic infection (bovine leukemia) or disease (parvovirus, distemper)
positive
84
Vaccination w high-titer vaccines -> positive PCR/ELISA test for ____________ with NO wild-type virus or disease (i.e. parvovirus)
7-10 days
85
___________ antibody result indicative of previous infection, previous vaccination, OR maternally-derived passive antibodies
positive
86
T/F- Antibody levels highly variable among animals – interpretation can be conclusive from a single sample
false
87
__________ results - specific virus/antibody NOT detected, indicative of NO infection
Exceptions: wrong timing, wrong choice of sample, wrong individual animal
negative
88
reasons for testing:
a) diagnosis / management of disease
b) certification of freedom from specific infections
c) disease surveillance
d) monitoring for public-health significance
all of the above
89
Detection of virus dependent on (3)
site, animal, and time
90
T/F - Virus replication does always coincides with observed clinical signs
false
91
T/F =- Multiple samples are vital – for both virus + antibodies
true
92
______ samples used for virus detection assays (PCR, ELISA)
unfixed
93
______ samples used for microscopic examination / immunocytochemical assays (viral antigens)
fixed
94
T/F - Vaccines do not prevent infection – used to prevent and manage viral disease by ‘priming’ the immune system to respond to exposure to the antigen
true
95
T/F - Exposure to the same antigen results in lower level + more rapid secondary immune response
false
96
T/F - Vaccine types vary in disease mitigation
true
97
vaccine types are mostly ___________, EXCEPT for rabies and circovirus (inactivated)
modified-live
98
herd immunity achieved between __________ vaccination, depending on how contagious the virus
70-90%
99
antibodies produced following viral infection (3)
IgG, IgA, IgM
100
for __________ spreading viruses (i.e. distemper) – high IgG titers + cell-mediated immunity are important
systemic
101
for _________ infection (i.e. influenza) – secretory IgA offers protection
local
102
Proof of protection is established by challenge of vaccinated animals with ___________ virus
wild-type
103
If a virus is intracellular or has established a latent infection, ___________ immunity is more important for protecting
cell-mediated
104
T/F - Serum IgG does not correlate w persistent / latent infections (i.e. retroviruses, alpha herpesviruses)
true
105
If viremia occurs, serum _______ can bind virus and block entry into cells
IgG
106
objectives of vaccination:
a) disease prevention
b) mitigation of disease
c) protection of unvaccinated population
all of the above
107
T/F - One approach to vaccination applies to all viral diseases
false
108
vaccines that protect from diseases that are endemic to a region, of public health significance, required by law, caused by highly infectious vaccines, those posing a severe risk of disease
i.e. canine parvovirus, distemper, adenovirus 2 – begin as early as 6w of age, at 2w intervals
core vaccines
109
vaccinated puppies (8w) are protected from exposure to WT virulent parvovirus at
10 weeks
110
most common cause of vaccine failure is _______ ________ interference
maternal antibody
111
vaccine designed to immunize against two or more strains of the same microorganism, or two or more microorganisms
Multivalent vaccine
112
T/F - Level + length of time of protection vary with individual vaccines and individual animals
true
113
vaccine ______________ is often due to incorrect storage, expiration, or incorrect administration
inactivation
114
Determination of __________ status is vital for assessment of animals with: unknown vaccination history, overdue vaccinations, those undergoing chemotherapy, immunosuppressive drugs, or history of adverse reactions
antibody
115
contain agents capable of replicating within the animal, yet have attenuated pathogenicity (non-virulent)
Modified live vaccines
116
derived from naturally-occurring pathogens, produced by generation of non-virulent virus by attenuation in cell culture
Modified live vaccines
117
Contain high titers of a low passage strain of the target virus – may produce a higher level immune response, likely to overcome low levels of maternal antibodies
Modified live vaccines
118
Choice for situation where multiple injections are not feasible, producing a higher level immune response (i.e. shelter animals)
Modified live vaccines
119
Decreased potential for allergic reactions
Modified live vaccines
120
Highly susceptible to inactivation – proper handling & storage is critical
Modified live vaccines
121
May acquire mutations in host & revert to virulence – rare, but requires monitoring
Modified live vaccines
122
stimulate a broad range of immune responses & long-lasting duration of immunity with administration of fewer dose; however, poses greater risk to animals
Live vaccines
123
engineered by incorporation of genes for a pathogen’s antigen proteins into a harmless carrier virus
Recombinant vector vaccines
124
Cannot induce a robust immune response in the host or revert to virulence or cause disease
Recombinant vector vaccines
125
deletion or inactivation of a virus gene that is required for virulence, while leaving the capability of virus to replicate intact (aka DIVA – differentiating infected from vaccinated animals)
Deletion vaccines
126
may be non-amplifying or self amplifying – lead to efficient generation of antigen-specific immune responses to inserted genes of target viruses
Ex) Venezuelan equine encephalitis virus – used as potential vaccine delivery platform
Ex) Alphavirus replicons – have structural proteins deleted, and replicate vector RANA in cytoplasm
RNA vaccines
127
RNA viruses target specific pathogens to produce prescription, and may include __________ vaccines against viral and bacterial pathogens
customized
128
non-infectious, no reversion to virulence, no shedding of virus after immunization; usually require a higher antigen mass, adjuvant, multiple doses, and frequent boosters
Inactivated vaccines
129
Stable in storage
Inactivated vaccines
130
Safe for pregnant and immune-suppressed animals
Inactivated vaccines
131
Require adjuvants
Inactivated vaccines
132
likely to induce hypersensitivity reactions, injection site-reactions (granulomas/abscesses). & sarcomas in cats (associated with adjuvants)
Inactivated vaccines
133
contain a portion of the organism – specific purified proteins that are not infectious
Subunit vaccines
134
DNA coding for antigenic proteins of a viral pathogen is directly injected into animals
DNA vaccines
135
any undesirable side-effect or unintended effect including the apparent failure to protect from the disease
adverse events
136
________ reactions (more common): pain, pruritis, alopecia, transient lameness
local
137
T/F - Reversion to virulence (i.e. MLV vaccines) is common with commercial vaccines for most viral pathogens
false
138
antiretroviral drugs that inhibit reverse transcriptase & nucleic acid synthesis
retrovir
139
inhibits viral DNA polymerase preventing further viral DNA synthesis
acyclovir
