Viruses Flashcards
(761 cards)
1
Q
viruses are __, they don’t replicate by division
A
assembled
2
Q
are non-enveloped or enveloped viruses more stable
A
non-enveloped
3
Q
what makes non-enveloped viruses more stable than enveloped
A
non-enveloped have a more sturdy capsule
enveloped only have a phospholipid envelope
4
Q
what are the 2 main ways non-enveloped viruses are transmitted
A
oral/fecal
fomites (non-living surfaces)
5
Q
how are non-enveloped viruses released from infected cells
A
lysis
6
Q
what do enveloped viruses use for attachment
A
glycoproteins
7
Q
what are the 3 main ways enveloped viruses are transmitted
A
respiratory droplets
sexual transmission
bite of insect
8
Q
enveloped and non-enveloped viruses both contain a capsid. what is the function of the viral capsid
A
enclose and protect viral genome
allow for attachment to host cells
9
Q
what part of a virus do we make antibodies against
A
capsid protein
10
Q
what is the function of polymerase enzymes present in some viruses
A
involved in transcription and replication of viral genome
11
Q
are matrix proteins present in enveloped or non-enveloped viruses
A
enveloped- between the nucleocapsid and envelope
12
Q
what are the 3 functions of matrix proteins in enveloped viruses
A
stabilize the organization of viral glycoprotein and the lipid envelope
direct the viral genome to intracellular sites of viral assembly
facilitate viral budding
13
Q
are DNA or RNA viruses more stable
A
DNA
14
Q
where do DNA viruses replicate
A
nucleus
15
Q
where do RNA viruses replicate
A
cytoplasm
16
Q
DNA viruses replicate in the nucleus using primers and DNA polymerase. who do the primers and DNA polymerase belong to
A
viral primers
host cell DNA polymerase (DNA dependent DNA polymerase)
17
Q
RNA viruses must provide their own __ needed for gene copying
A
RNA dependent RNA polymerase
18
Q
do DNA or RNA viruses lead to more persistent infections with latent lifelong infections possible
A
DNA
19
Q
are DNA or RNA viruses more prone to mutations, why
A
RNA
RNA polymerase do not have proofreading ability
20
Q
what are the 7 steps to viral replication
A
attachment
penetration
uncoating
macromolecular synthesis (early mRNA/protein synthesis, replication of genome, late mRNA/protein synthesis)
post-translational modification
assembly of new virus
release
21
Q
what are the 2 methods that can be used by enveloped viruses for penetration and uncoating
A
fusion
endocytosis and acidification
22
Q
how does fusion occur in the penetration uncoating step of enveloped virus replication
A
lipid bilayer of viral envelope fuses with host cell membrane
23
Q
how does endocytosis and acidification in the penetrating uncoating step of enveloped virus replication occur
A
host cell cytoplasmic membrane wraps around the virus and brings it in the cell
24
Q
what are the 2 methods that can be used by non-enveloped viruses in the penetrating uncoating step of viral replication
A
endocytosis
direct entry through injection into a pore
25
how does + sense RNA virus differ from - sense in terms of RNA dependent RNA polymerase
+ sense must make RNA dependent RNA polymerase
- sense have preformed RNA dependent RNA polymerase
26
where do DNA vs RNA viruses assemble
DNA- in nucleus
RNA- in cytoplasm
27
how are non-enveloped viruses released from the host cell
rupturing through cell membrane
28
how are enveloped viruses released from the host cell
budding through outer membrane
29
where do enveloped viruses get their envelope from
host cell membrane
30
does enveloped or non-enveloped virus release sometimes lead to cell lysis
non-enveloped
31
what are the 3 main phases of a viral growth curve
infection
eclipse
latent
32
what happens during the eclipse period of a viral growth curve
uncoating and appearance of new virions in cell
33
what happens during the latent period of viral growth curve
more and more virus is released from the host cell
34
what is viral burst size
the number of viruses released from each host cell
35
what is antigenic drift
slow accumulation of point mutations that can lead to new strains
36
what is antigenic shift
major rapid change in genome due to reassortment
37
does antigenic drift or antigenic shift occur in all viruses
drift
38
what is a needed characteristic for viruses to perform antigenic shift
must carry their genome in segments
39
what virus does antigenic shift occur in
influenza A
(in birds, humans, marines-->if encounter each other= exchange segments= new strain)
40
what occurs with defective viruses
they got into the host cell but need another helper virus to replicate
41
what are pseudovirions
only capsid with no viral genome so they can't replicate
42
phenotypic mixing can only occur between __ or __ viruses
same or similar
43
what occurs with phenotypic mixing (transcapsidation)
viral genome is incorporated into a capsid with its own proteins and other viral capsid proteins
44
what is pseudotype formation
nucleocapsid of one virus acquires an envelop from another virus
45
what is an effect of phenotypic mixing
it can expand the host range
46
what occurs with viral recombination
nucleic acid strand breaks and rejoins in a different way
*if this occurs between 2 viral genomes, it results in progeny with phenotypic and genotypic differences from either of the original 2 viruses
47
what occurs with viral reassortment
in viruses with segmented genomes, the segments are mixed from 2 or more parental viral genomes, creating a new combination
48
what is a requirement for recombination or reassortment to occur
the viruses must be replicating in the same cell at the same time
49
does viral reassortment or recombination have a greater effect
reassortment
50
is adenovirus enveloped or nonenveloped
nonenveloped
51
virions of adenovirus are resistant to __ but disabled by __
temperatures up to 56C
chemicals
disabled by citric acid
52
what is the main virulence factor of adenovirus for attachment
fiber protein
53
what factor of adenovirus is associated with different strains
fiber protein
54
what serotypes of adenovirus are associated with the most worrisome symptoms
4 and 7
55
how are adenovirus genes classified
early or late
56
what is involved in adenovirus early genes
host cell takeover
57
what is involved in adenovirus late genes
viral structures
58
when given just the gene of adenovirus, how can you determine if it is an early or late gene
early start with E
59
what are the steps of adenovirus infecting a cell
fiber protein binds to CAR receptor
clathrin coated pit and endosome form
endosomes acidified
capsid travels to nucleus, disassembles and releases DNA
60
the main way of adenovirus transmission is through ___, although since it is a nonenveloped virus, it can also be transmitted through __
respiratory droplets
fecal oral contact
61
what is the main cause of swimming pool conjunctivitis
adenovirus
62
in terms of when we are contagious and when symptoms appear, what is it like for adenovirus
contagious 2-3 days before symptoms start
63
what is the incubation period for adenovirus
1-9 days
64
larger respiratory droplets usually cause __ (upper or lower) respiratory tract infection and __ (more or less) severe symptoms
upper
less
65
adenovirus is persistently secreted in __ weeks after initial infection
stool
66
adenovirus is most common in what age group
<14 years
67
why are those in the military given a serotype 4 and 7 vaccine against adenovirus
since it is spread by droplets, it is given to present epidemics in camps and barracks
68
what virus causes acute febrile pharyngitis
adenovirus
69
what are the symptoms of acute febrile pharyngitis caused by adenovirus
sore throat, cough, stuffy nose
70
what serotypes of adenovirus are the most common cause of acute respiratory distress caused by adenovirus
4 and 7
71
what virus causes acute respiratory distress
adenovirus
72
what 2 viruses causes pneumonia
adenovirus
varicella-zoster virus (VZV) in adults
73
what patients are at the greatest concern for developing fatal pneumonia caused by adenovirus
kidney transplant patients because the virus sticks around in the kidneys
74
what is the symptom progression of follicular conjunctivitis (swimmers pink eye) caused by adenovirus
incubation is 6-9 days, then there is development of sore throat, fever, and conjunctivitis
75
what virus causes epidemic keratoconjunctivitis
adenovirus
76
what population is epidemic keratoconjunctivitis most common in
industrial worker- respiratory droplets mix with duct and get in the eye
77
what are the symptoms of epidemic keratoconjunctivitis
edema, pain, photophobia
can last for months
78
what virus causes acute hemorrhagic cystitis
adenovirus
79
what are the symptoms of acute hemorrhagic cystitis caused by adenovirus
hematuria
increased urinary frequency/urgency
pain with urinating
80
what virus causes acute gastroenteritis
adenovirus
81
acute gastroenteritis caused by adenovirus is frequently associated with what population diarrhea and gastroenteritis
childhood
82
what is the main concern about acute gastroenteritis caused by adenovirus
it can lead to intussusception
83
what are the 2 urinary/GI symptoms caused by adenovirus
acute hemorrhagic cystitis
acute gastroenteritis
84
since adenovirus fibers are different for different strains, what does this tell us about our immunity
response is serotype specific- we make IgG against the specific fiber
85
since we produce IgG against adenovirus, we have protection against reinfection but we still need a ___ once the virus is in the cell
T cell
86
why are infections of adenovirus rare for infants in the first 6 months
maternal IgG protects
87
what is the main way of testing for adenovirus
what is another slightly less common way
PCR
serology
88
isolation/growth of cultures cells is not the preferred method for adenovirus diagnosis, although it is performed for what type of patients
kidney transplant
89
if a patient dies of adenovirus, what is seen in autopsy
basophilic nuclear inclusion bodies in lungs, brain, and kidneys
90
what is seen histologically in a patient with adenovirus
inclusion bodies in the nucleus
91
what is the ID dose for adenovirus
1 virion
92
is parvovirus enveloped or nonenveloped
nonenveloped
93
what serotype of parvovirus infects human
B19
94
is parvovirus single or double stranded DNA genone
single
95
what is the smallest DNA virus
parvovirus
96
where does parvovirus replicate
in erythrocyte precursor cells in S phase (mitotically active cells)
97
parvovirus infects erythroid precursor cells due to the presence of what
receptor ganglioside (blood group P antigen)
98
what allows for parvovirus to replicate quickly
it uses its own self primers that our DNA polymerase then used to copy it
99
what allows for parvovirus to replicate quickly
it uses its own self primers that our DNA polymerase then uses to copy
100
where in the body does parvovirus replicate
bone marrow
101
the globoside on erythrocyte precursor cells is an __ that allows entry into the cell
integrin
102
does parvovirus just stay in bone marrow
no, it can be found in organs throughout the body
103
how is parvovirus spread
respiratory droplets
blood and blood products
104
what is the main symptoms of parvovirus
rash and joint pain
105
rash and joint pain occur in parvovirus due to a type __ HSR to virions
III
106
in what patients is parvovirus of greatest concern
patients with pre-existing chronic amenia
*these patients already have low RBC count. lysis of additional RBC could be fatal and lead to aplastic crisis
107
parvovirus is most common in what age group
3-7
108
parvovirus in childhood mainly causes __
parvovirus in adulthood mainly causes __
rash
joint pain
109
who is at most risk with blood infusions in terms of parvovirus infection
those who are already anemic
110
when is parvovirus most common
late winter-early summer
111
is parvovirus able to cross the placenta
yes
112
what virus causes erythema infectiosum
parvovirus
113
what symptoms occur in the first stage of parvovirus
fever, runny nose, headache, GI symptoms
114
what symptoms occur in the second stage of parvovirus, after 2-5 days
erythematous maculopapular rash on face (slapped cheek) then truck and extremities (lacey)
115
after __ day of parvovirus infection, leukocyte count increases to try to clear the virus
14
116
low hemoglobin count occurs at what stage of parvovirus (along with what symptoms)
rash/muscle aches
117
an in utero infection with parvovirus can lead to ___
hydrops fetalis
118
what is hydrops fetalis
accumulation of fluid in at least 2 fetal compartments (subcutaneous tissue/scalp, pleura, pericardium, or abdomen)
119
arthropathy caused by parvovirus mainly affects what joints
small joints of hands and feet symmetrically
120
what is believed to cause arthropathy and rash caused by parvovirus
type III HSR where immune complexes are formed by parvovirus and IgG
121
in anemic patients, parvovirus can lead to ___
transient aplastic crisis
122
what virus can cause transient aplastic crisis in anemic patients
parvovirus
123
when the rash or joint pain develop from parvovirus, are you still contagious
no
124
IgG against parvovirus starts being made how many days after infection
2 weeks
125
what are the 2 ways to test for parvovirus
ELISA for B19 IgM or IgG
PCR
126
parvovirus in children and adults is usually benign and self limiting, but in those with an underlying anemic condition, treatment should be __ or __
blood transfusion
immunoglobins
127
are papillomaviruses enveloped or nonenveloped
nonenveloped
128
are polyomaviruses enveloped or nonenveloped
nonenveloped
129
papillomaviruses cause what symptom in healthy people
warts
130
although papillomaviruses generally only cause warts in healthy people, it may lead to __
throat/genital/cervix cancers
131
what type of cells does HPV infect
rapidly dividing epithelial
132
what 4 serotypes pose the greatest health concern (main health concern for HPV is genital/throat cancer)
16
18
31
45
133
the main concern for HPV is the development of ___
genital cancers
134
what serotype of HPV can cause oropharyngeal cancer
16
135
is HPV single or double stranded DNA genome
double
136
what does the E1 gene of HPV do
promotes viral DNA replication
137
what do the E6 and E7 genes of HPV do
they can become immortalizing genes
138
what does the E5 gene of HPV do
activates epithelial growth factor receptor to promote growth
139
what is the advantage provided to HPV by the E5 gene activating
the more the host cell divides, the more virus that will be replicated since the virus infects epithelial cells
140
how does HPV enter the body
through skin breaks
141
what causes wart formation in those with HPV
rapid, increased cell turnover in the spinosum epithelial layer
142
what layer of the epithelium do HPV viruses assemble in
granulosum
143
how are HSV viruses released once they make their way up the layers of the skin
they're shed with dead keratinocytes
144
where is the usual site of entry of HPV
hand
foot
throat
cervix
*skin or oral mucosa
145
what may be a cause of a wart caused by HPV becoming a cancer
HPV DNA is incorporated into the tumor cell genome
146
HPV persists in what layer of the epithelium
basal
147
skin warts (mostly on hands and feet) caused by HPV are usually caused by HPV types _
1-4
148
the initial infection of HPV is usually with what age group
childhood or early adolescence
149
what is the incubation period for HPV that causes skin warts before warts appear
3-4 months
150
benign head and neck tumors caused by HPV are usually caused by what HPV types
6 and 11
151
benign head and neck tumors caused by HPV are usually on what surfaces
mucosal
152
what is the general structure of head or neck warts caused by HPV types 6 and 11
stalk with a rough surface
153
do skin warts or head/neck mucosal warts usually require surgical removal
head/neck
154
what are the 3 areas most likely to find head/neck tumors caused by HPV
oral
laryngeal
conjunctival
155
what is the main concern with benign laryngeal tumor caused by HPV
it can obstruct the airway
156
what HPV type causes anogenital warts
6 and 11
157
what is the main symptom of HPV caused by strains 6 and 11
condylomata acuminata (warts)
158
what HPV serotypes are associated with cervical intraepithelial neoplasia and cancer in women
16 and 18
159
what is cervical dysplasia caused by HPV
the 1st neoplastic changes noted by microscopy
160
cervical/oral mucosa cancer caused by HPV can be monitored/diagnosed by what 2 methods
cytology
histology
161
how does histology differ from cytology for epithelium sampling for cervix/oral HPV infection
cytology- scrape epithelial cells
histology- take out a tissue sample
162
what type of epithelium with mucosa does HPV infect
stratified squamous non-keratinized
163
cytology classifies stages of HPV mucosa cancer into __ or __
LSIL (low- very mild dysplasia)
HSIL (high- moderate to sever dysplasia)
164
histology classifies stages of HPV mucosa cancer into __, __, and __
CIN 1 (mild dysplasia)
CIN 2 (moderate dysplasia)
CIN 3 (severe dysplasia-->in situ carcinoma)
165
cancer development through HPV infection takes how long to develop
months-decades
166
over expression of what 2 genes leads to mucosal cancer development caused by HPV
E6 and E7
167
what is the effect of E6 on HPV mucosal cancer progression
it degrades p53, leading to loss of tumor suppression
168
what is the effect of E7 on HPV mucosal cancer progression
it keeps gene transcription on by binding to Rb in the spot where E2F would be bound
*unbound EF2= cell cycle progression
169
HPV transmission is through direct contact with the virus through breaks in skin. this can occur by what mechanisms
fomites
sexual intercourse
passage of baby through an infected birth canal
chewing warts (children)
asymptomatic shedding
170
what virus can cause both cutaneous and mucosal warts
HPV
171
what is the main cause of cervical cancer
HPV infection
172
what virus is the main causes of cervical, vaginal, anal, penile, and oropharyngeal cancers
HPV
173
what 2 HPV genes are oncogenes
E6 and E7
174
what type of immunity is important for HPV clearance
cell mediated
175
if microscopy is used to confirm HPV causing warts, what is visualized
hyperplasia of prickle cells (in spinosum layer)
hyperkeratinosis
176
what is the main method to diagnose papillomavirus
what can also be used
pap smear
PCR for HPV gene
177
a pap smear positive for papillomavirus shows the presence of what
koilocytotic squamous epithelial cells (vacuolated, rounded, and in clumps)
178
pap smears are required every __ years from age __-__
3 years
25-65
179
what is recommended as the next step if cytology shows low grade changes
cytology in 1 year or immediate PCR
180
if initial pap smear is slightly abnormal and a PCR test following is positive for HPV, what happens next
what is the PCR is negative for HPV
+= colposcopy (biopsy of cervix)
-= cytology in 3 years
181
what are the stimulators of inflammation in HPV infection
type 1 interferon
182
what drug can be used to increase cell mediated immunity to treat HPV wart infection
imiquimod (Aldara)
*drives antiviral response
183
what drug is used to kill HPV infected cells
cidofovir
184
how does cidofovir work
disables viral DNA Polymerase
185
what can cidofovir be used against
viruses that have their own DNA polymerase
186
what type of vaccine is the HPV vaccine
subunit
187
what is the HPV vaccine made of
empty virus with HPV capsid protein so our immune system will make immunity against the capsid protein
188
at what age is the vaccine for HPV (Gardasil/Cervarix) recommended
age 12 (but is approved for use up to age 45)
189
what 2 viruses are part of the human polyomaviruses
JC
BK
190
JC and BK (human polyomaviruses) usually only infect what population
immunocompromised
191
what is the relavance of the simian (monkey) polyomavirus SV40
it is used as an experimental model for oncogenic viruses
192
most people are infected with both JC and BK viruses by what age
15
193
polyomaviruses are spread by what route
respiratory
194
although human polyomaviruses usually don't cause infection in immunocompetent patients, what can happen under conditions of immunosuppression
latent infections can be reactivated
195
what is the progression of JK/BK viruses once they enter the respiratory tract
primary viremia, multiplication in the kidneys, secondary viremia
in immunocompetent, the virus is latent indefinitely in the kidneys
in immunocompromised, BK multiplies in the urinary tract, JK causes viremia in the CNS
196
what is the effect of BK virus in the immunocompromised
viremia and possible hemorrhagic cystitis
197
what is the effect of JC virus in the immunocompromised
CNS involvement-->progressive multifocal leukoencephalopathy
198
BK an JC infections are especially worrisome in what patients
those with kidney transplant
199
BK and JC virus are found in what sample type in immunocompromised
urine (in 40%)
200
what virus causes progressive multifocal leukoencephalopathy
JC (polyomavirus)
201
what is the effect of progressive multifocal leukoencephalopathy infection caused by JC
myelin damage
(HA, clumsiness, aphasia, memory loss, vision problems, extremity weakness)
202
although there is no treatment for polyomavirus, reactivation can be treated by treating ___
immunosuppression
203
is poxvirus enveloped or nonenveloped
enveloped
204
most DNA viruses replicate in the nucleus. the exception to this is __ which replicated in the cytoplasm
poxvirus
205
what makes the shape of poxvirus unique
it is large, ovoid shape
206
the structure of poxvirus contains __
lateral bodies
207
lateral bodies are seen with poxvirus that give the inside of the virus a dog bone appearance. do the lateral bodies contain the DNA
no
208
where does poxvirus replication occur
cytoplasmic Guarnieri bodies
209
what is the advantage of Guarnieri bodies formed by poxvirus in host cell cytoplasm
they allow the virus to "hide" and complete assembly
210
what are the 2 ways in which poxvirus can escape from Guarnieri bodies
lysis (1 membrane)
exocytosis (wrapped with external membrane) and pushed out of cell using actin tail
211
what drug is used in poxvirus to decrease the amount of viral release
tecovirimat
212
how does tecovirimat for poxvirus infection work
external envelope formation
213
what are the 2 ways in which poxvirus can be transmitted
direct contact (respiratory droplets)
fomites
214
what are the 2 forms of smallpox infections causes by poxvirus
variola minor (mild symptoms)
variola major (severe symptoms)
215
where are the pocks located in smallpox vs chickenpox
smallpox- whole body including palms and soles
chickenpox- not on palms and soles
216
how are pocks caused by small pox resolved
scab in 1-14 days, fall off in 14-28 days
217
smallpox pocks are __
chickenpox pocks are __
(superficial/deep)
smallpox- deep
chickenpox- superficial
218
do the pocks vesicles collapse on puncture in smallpox or chickenpox
chickenpox
219
the smallpox vaccine was introduced in the __, allowing for decline and extinction
60's
220
what 4 major factors allowed for the eradication of smallpox
humans were the only host
1 single stable serotype
effective vaccine
consistent and distinctive disease presentation (no asymptomatic cases)
221
who still receives a smallpox vaccine
military
222
mokeypox spread is associated with what animal
prairie dog
223
what are the symptoms of monkey pox
fever, HA, muscle aches, swollen lymph node, chills, pimple-like rash
*similar to smallpox
224
how is monkeypox transmitted
contact with lesions
respiratory secretions
225
what drug may be prescribed for patients at risk for monkey pox complications
tecovirimat
226
post exposure to monkeypox is treated prophylactically with __ within __ days of exposure
vaccines
4
227
what are the 2 vaccines for monkeypox
JYNNEOS
ACAM2000
228
JYNNEOS and ACAM2000 are both what type of vaccine
live virus
229
how does JYNNEOS and ACAM2000 vaccine differ in terms of replication
JYNNEOS does not replicate efficiently in human cells
ACAM2000 replicates at the inoculation site
230
how does JYNNEOS differ from ACAM2000 in terms of number of doses and amount of time to get an immune response
JYNNEOS- 2 injections 4 weeks apart, immune response after 2 weeks of 2nd dose
ACAM2000- 1 injection, immune response after 4 weeks
231
what type of virus is molluscum contagiosum virus
poxvirus
232
how is molluscum contagiosum virus (a poxvirus) spread
direct contact
fomites
sexual transmission
233
what is the main symptom of molluscum contagiosum virus
white, painless nodules (not on the palms and soles) usually on face and occasionally on the trunk
234
molluscum contagiosum virus is most common in what populations
children
immunocompromised
235
what is seen with nodule biopsy with molluscum contagiosum virus
eosinophilic inclusion bodies (Henderson-Patterson bodies) with virus particles
236
nodules caused by molluscum contagiosum virus may have a pearly white appearance due to what
lysis of cells
237
poxvirus diagnosis is usually based on characteristic skin lesions and rashes, however what can also be done
sample collection from "crust" and vesicular fluid
*monkeypox can be detected through use of PCR
238
ORV poxvirus can be acquired from __
heard animals (most common in farmers)
239
ORV virus presents as __
same as original smallpox virus
240
is herpesvirus DNA or RNA virus
DNA
241
is herpesvirus enveloped or non-enveloped
enveloped
242
as herpesvirus infects a host, how does it adjust its genone
circularizes
243
what are the 2 main characteristics of herpesvirus in terms of its infection
establishes latent infections
persists indefinitely in infected hosts (cell mediated immunity keeps it in check)
244
what is the difference between alpha, beta, and gamma herpesvirus in terms of replication time
alpha- rapid replication
beta- slow replication
gamma- rapid replication
245
Kaposi sarcoma associated herpesvirus is also called __
HHV-8
246
alpha herpesviruses establish latency where
nerve ganglion
247
beta herpesviruses establish latency where
monocytes, lymphocytes, or neutrophils
248
gamma herpesviruses establish latency where
B lymphocytes
249
what is important about the tegument of herpesvirus
it contains viral proteins and enzymes for immediate viral infection following infection
250
what allows for herpesvirus entry into the cell
glycoproteins
251
epstein barr virus uses what 2 receptors
CR2 (aka CD21) on B cells and HLA class II
type 2 complement receptor to activate B cells
252
what are the 2 main receptors used by most viruses that infect mucosal epithelial cells
heparin sulfate and integrin
253
once the herpesvirus fuses with a host cell, what happens
virus penetrates, uncoats, capsid is directed to the nuclear pore where it injects DNA directly into the nucleus
254
what 2 enzymes are produced by herpesvirus that allows for anti-viral drug targeting
viral DNA polymerase
thymidine kinase
255
what are the 2 methods that can be used by viruses for proliferation
encode proteins that forces cells to proliferate, forcing cell to make more DNA building blocks
viral genome encodes for enzymes required for DNA replication
256
what is required for herpesvirus to become effective and mature
proteolytic cleavage
257
herpesvirus genonmic concatemers are cleaved and packaged into pre-assembles capsids in the __
nucleus
258
where are tegument proteins in herpesvirus expressed
endosome
259
what is the difference between the 2 infection types, lytic and latent, caused by herpesvirus
lytic involves making and releasing virus
latent involves the virus being kept in the cell nucleus as an episome until it can reactivate again, and is copied along with the host cell
260
what is the only virus that performs latent infections
herpes
261
what can cause reactivation of herpesvirus from latency
stress
immunosuppression
corticosteroids
(anything that shifts the attention of the immune system)
262
herpes simplex virus-1 (HSV-1) mainly causes infection above or below the waist
above
263
herpes simplex virus-2 (HSV-2) mainly causes infection above or below the waist
below
264
how is HSV-1 spread
direct contact with mucosal tissue
265
how is HSV-2 spread
sexual transmission
266
do most children have HSV-1 or HSV-2 by the age 5
HSV-1
(kissing)
267
HSV-1 and HSV-2 share approximately 50% homology but can be distinguished by what testing methods (2)
antigenically
PCR
268
is herpesvirus reported to DOH
no
269
over the past decade, has the percentage of people with genital herpes increased or decreased
decreased
270
where is the initial site of infection of HSV
mucoepithelial cells
271
what causes the lesions caused by HSV
lytic infection leads to cell lysis
272
what is seen histologically for someone with HSV (3)
ballooning degeneration of epithelial cells (cells get filled with virus)
multinucleated giant cell formation
eosinophilic intracellular inclusion bodies
273
HSV-1 remains latent in what neural ganglion
trigeminal
274
with reactivation of HSV-1, how does the virus travel
back down the axon to the original site of infection
275
what keeps HSV-1 from spreading to the CNS
cell mediated immunity
276
what prevents exogenous infection with HSV
production of neutralizing antibodies against HIV envelope glycoproteins
277
what limits early infection of HSV
antibody dependent cellular cytotoxicity
278
cytotoxic T lymphocyte response develops how long after infection with HSV
2 weeks
279
what are 4 ways in which HSV are able to interfere with our immune system
cells fuse together
inhibit TAP protein loading on MHC class I
express proteins that interfere with IFN signaling pathways
glycoprotein E and I form a receptor for IgG Fc region, pulling IgG out of circulation and inhibiting IgG from activating complement
280
HSV-2 remains latent where
sacral ganglia
281
how are HSV-1 and HSV-2 spread
contact with saliva, vaginal secretions, or lesion fluid
282
HSV-1 is generally transmitted __
HSV-2 is generally transmitted __
HSV-1= orally
HSV-2= sexually
283
how are HSV-1 and HSV-2 able to undergo recombination
mixing of mucous membranes
284
children are more at risk for __
adults are more at risk for __
(HSV-1 or HSV-2)
children- HSV-1
adults- HSV-2
285
how does HSV pose a risk to physicians/nurses/dentists
formation or herpetic whitlow on the fingers
286
what is the main symptom of HSV-2 infection
recurrent lesion is a painful, clear wet looking blister on an erythematous base
287
what is the concern about HSV infection in immunocompromised
HSV-1 and HSV-2 can lead to meningitis
288
does HSV-1 or HSV-2 cause neonatal HSV
HSV-2
289
what virus causes oral herpes
HSV-1 or HSV-2
290
what is the main virus that causes herpes labialis and gingivostomatitis
HSV-1
291
what are the 3 main symptoms of herpes pharyngitis
fever
sore throat
vesicular lesions on pharynx and palate
292
is herpes pharyngitis usually the result of a primary or reactivated infection
primary
293
what virus causes cold sores
HSV (herpesvirus)
294
where do the lesions caused by HSV appear in herpes labialis
corners of mouth or next to lips
295
what occurs with recurrent episodes of herpes labialis causes by HSV
less severe
more localized
shorter duration
recurrence at same site as original infection
296
what is seen as a sequela of increased T cell response to HSV
herpetic keratitis
297
what occurs in herpetic keratitis
neovascularization
cloudiness in one eye
blindness
corneal damage
298
what are the 3 main results of recurrent infection with HSV in herpetic keratits
permanent scarring
corneal damage
blindness
299
what HSV causes herpes encephalitis
HSV-1
300
herpes encephalitis mainly affects what part of the brain
inflammation of temporal lobes
301
what is the most common cause of viral sporadic encephalitis
HSV-1
302
where does herpetic whitlow localize
fingers
303
herpetic whitlow is most common in what patients (3)
people with genital HSV infection
thumb-sucking children
nurses/physicians
304
herpes gladiatorum differs from herpes whitlow based on the fact that herpes whitlow involves infection of the fingers, while herpes gladiatorum is focuses at what 3 main body sites
neck
face
arms
305
how is herpes gladiatorum spread
cuts/abrasion in the skin
*now sexually transmitted
306
herpes gladiatorum is most common in what population
wrestlers
307
eczema herpeticum is acquired in what population
children with eczema
308
what herpesvirus causes genital herpes
HSV-1 and HSV-2
309
what virus causes painful lesions of the genitalia
herpesvirus (HSV-1 and HSV-2)
310
what is the progression of symptoms like for a female with genital herpes
initial itching-->painful lesion
-->mucoid discharge
311
HSV proctitis (inflammation of the anus and lining of the rectum) accompanies what herpes infection
genital herpes
312
in genital herpes, what develops before lesions appear
general flu-like symptoms
313
what is the incubation period of HSV-1 and HSV-2 for genital herpes
5 days
314
healing of genital herpes begins after how long
7-10 days
315
latency of genital herpes is established after how many days
approximately 21
316
what is a characteristic of recurrence with genital herpes
every recurrence will have less symptoms and faster healing
317
what is the main way that neonatal HSV is acquired
if mother has a primary HSV-2 infection at time of delivery
318
what are the 2 main symptoms of neonatal HSV
sepsis (systemic inflammation)
vesicular lesions
319
what is the main concern of neonatal HSV
is can reach the liver, lungs, or CNS
progression to the CNS can result in death, mental disability, or neurologic disability without treatment
320
what are the 2 main ways in which HSV is diagnoses
PCR
lesion scrape and do a tzanck smear
321
what is the main drug of choice for HSV infection
acyclovir
322
acyclovir, used to treat herpesvirus, is a derivative of what __
nucleoside guanosine
323
how does acyclovir, a commonly prescribed antiviral for herpesvirus, work
the viral thymidine kinase activates the drug and the host enzymes completes the process to stop DNA replication
(acyclovir triphosphate competes with guanosine triphosphate to inhibit the polymerase and cause termination of the growing viral DNA chain)
324
what 2 mutation in the cell can prevent acyclovir from working
viral thymidine kinase
DNA polymerase
325
valacyclovir is a commonly used drug to treat HSV in what population
pregnant
326
pencyclovir is used as an antiviral against what viral infection
HSV
varicella-zoster virus
327
what antiviral drug is absorbed better by cells of the liver and intestinal lining than acyclovir
famcyclovir
328
gancyclovir is used an antiviral for what infection
cytomegalovirus (CMV)
329
what virus causes chickenpox and shingles
varicella-zoster virus (VZV)
330
how is varicella-zoster virus (VZV) spread
respiratory droplets or direct contact
331
varicella-zoster virus (VZV) replicates in what 3 cell types
T cells
epithelial cells
epidermal cells
332
what allows for varicella-zoster virus (VZV) to cause viremia
the virus infects T cells which travel in lymphatics
333
what is the vesicle progression like in varicella-zoster virus (VZV)
macules-->papules-->vesicles
-->pustules-->crusts
334
who is at more risk for severe disease caused by varicella-zoster virus (VZV)
(children or teens/adults)
teens/adults
335
what is the incubation period for varicella-zoster virus (VZV) before symptoms occur
14 days
336
what are the 2 main symptoms of varicella-zoster virus (VZV) causing chickenpox
fever
red vesicular itchy wet looking blisters
337
chickenpox begins on the __, then spread to the __ and __
(what part of the body)
chest
face
extremities
338
varicella-zoster virus (VZV) viral replication first occurs in __, then __before rash and fever begin
regional lymph nodes
liver/spleen/other organs
339
what virus can cause interstitial pneumonia if infection occurs in adulthood
varicella-zoster virus (VZV)
340
what is the most common complication of varicella-zoster virus (VZV) in children
secondary staph or strep infection
341
what virus can cause acute cerebellar ataxia in children
varicella-zoster virus (VZV)
342
what is the most common neurological sign of acute cerebellar ataxia in children caused by varicella-zoster virus (VZV)
truncal ataxia
343
congenital varicella infection can cause what problems in newborns
damage to CNS
eye problems
Horner syndrome
intellectual disabilities
death
344
what weeks of gestation have the greatest risk of congenital varicella syndrome in newborns
week 13-20
345
maternal varicella that developes within __ days before or __ days after delivery is especially high risk for the infant
5 days
2 days
346
the common name for herpes zoster is __
shingles
347
herpes zoster (shingles) is a recurrence of a latent __ infection
varicella (chickenpox)
348
how does the rash location in shingles differ from chickenpox
shingles rash is limited to a dermatome (only one area)
349
what virus causes postherpetic neuralgia
herpes zoster (shingles)
350
what virus causes "successive crops of papules"
chickenpox (herpes varicella)
351
what is involved in a Tzanck smear for viruses
swab of an open lesion
352
what are the 2 main drugs to treat herpes zoster virus (shingles)
acyclovir
famciclovir
353
varicella zoster immunoglobin, which is available for immuocompromised, staff exposed, or newborns exposed, is what type of immunity
passive
354
varicella virus causes ___
herpes zoster causes __
chickenpox
shingles (reactivation of varicella)
355
what type of vaccine is the varicella vaccine for children
live attenuated
356
what type of vaccine is shingrix for shingles
subunit
357
__+__ make up the shingrix vaccine for shingles
glycoprotein E (used for attachment)
adjuvant
358
the adjuvant of shingrix vaccine is made of __ which stimulates __ for proinflammatory response
lipid A
TLR 4
359
varicella vaccine should be administered at what age
12-15 months
360
what are the 3 alpha herpesviruses
HSV-1
HSV-2
varicella-zoster virus (chickenpox/shingles)
361
what are the 2 gamma herpes viruses
epstein barr virus (mono)
Kaposi's sarcoma (HHV-8)
362
epstein barr virus causes what main infection
mononucleosis (mono)
363
epstein barr virus is part of what virus family
herpesvirus
364
epstein barr virus is associated with what 3 other conditions
Burkitt's lymphoma
Hodgkin disease
nasopharyngeal carcinoma
365
what virus causes heterophile antibodies
epstein barr virus
366
what does it mean to say that epstein barr is heterophile antibody positive infection mononucleosis
lots of IgM is made with no specific antigen target
367
what is the main cause of mononucleosis
epstein barr virus
368
what 2 viruses can cause mononucleosis
epstein barr
cytomegalovirus
369
epstein barr virus binds and becomes latent in what cells
mature naive B cells
370
epstein barr virus binds to what receptor
CD21 using MHC II as a coreceptor on B cells
371
in epstein barr virus original infection, what cytokines are released
IL-6-->proinflammatory
IL-10-->keeps T cell response under control
372
once epstein barr virus infects a cell, what process does it block, how
apoptosis by blocking Bcl2 expression
373
epstein barr virus usually infects epithelial cells located where
oropharynx and nasopharynx
374
epstein barr virus causes an increase in what 2 cell types
B and T cells
375
what 2 epstein barr virus genes are expressed in both the lytic and lysogenic phase
EBNA-2
EBNA-3
376
what 2 epstein barr virus genes are viral oncogenes
EBNA-2
EBNA-3
377
nonproliferating memory B cells that act as viral reservoirs for epstein barr virus express what 2 genes of the virus
EBNA-1
LMP-2 (latent membrane protein)
378
how does the lytic stage differ from the latent stage of epstein barr virus in terms of gene expression
lytic- all genes are expressed
latent- episome is formed and virus "hides out" without expressing any genes
379
what are the 3 potential outcome of epstein barr virus infection
replicate in B cells or epithelial cells
stimulate and immortilize B cells
cause latent infection of B cells in the presence of other T cells
380
atypical lymphocytes (Downey cells) are characteristic histologically in what virus
epstein barr virus
381
what type of cells are atypical lymphocytes seen in epstein barr virus
T cells
382
what is usually the first sign of mononucleosis
rash
383
what are 4 complications that can result from mononucleosis infection
splenic rupture
autoimmune hemolytic anemia
meningoencephalitis
guillan barre syndrome
384
what are the 4 main symptoms of epstein barr virus
cervical lymphadenopathy
exudate on tonsils
hepatosplenomegaly
papular rash
385
what is the incubation period of epstein barr virus
up to 2 months
386
what test is used to diagnose epstein barr virus mononucleosis
monospot
387
how does the monospot test for epstein barr virus work
patient serum is added to horse RBC to detect if there is IgM that binds to non-specific antigens
(increased heterophilie antibodies (IgM) due to epstein barr= more clumping)
388
what virus causes oral hairy leukoplakia in very immunocompromised patients or those with AIDS
epstein barr
389
what virus causes Burkitt's lymphoma
epstein barr virus
390
burkett's lymphoma is a cancer of what cells
B
391
what virus can cause nasopharyngeal carcinoma
epstein barr
392
epstein barr virus lymphoproliferative disease occurs with what 2 main groups of patients
immunocompromised
after transplant (immunosuppression)
393
what is the main symptom of epstein barr virus lymphoproliferative disease
mass lesions in organs (increased B cells in organs)
394
what are the 3 main risk factors for developing epstein barr virus lymphoproliferative disease
primary infection
low production of IFN-gamma or TNF-alpha
T cell depleted bone marrow
395
there is increasing evidence that what virus may be associated with multiple sclerosis
epstein barr
396
what virus is associated with primary effusion lymphoma
Kaposi's sarcoma herpes virus (HHV-8)
397
what is the main symptoms of HHV-8
vesicular lesions spread throughout body on epithelial surfaces
398
how is HHV-8 transmitted
sexual transmission
399
what are the 3 beta herpesviruses
cytomegalovirus
HHV-6
HHV-7
400
what virus is the most common cause of congenital defects
cytomegalovirus
401
what virus is the most common opportunistic pathogen in immunocompromised patients such as transplant patients
cytomegalovirus
402
how is cytomegalovirus spread
bodily secretions oral and sexual
403
what cells does cytomegalovirus primarily infect
epithelial T cells and macrophages
404
where does cytomegalovirus establish latency
T cells and macrophages
405
what is the main factor that allows for resolution of cytomegalovirus
cell mediated immunity
406
epstein barr virus and cytomegalovirus both cause mononucleosis. which is heteophile antibody positive
epstein barr virus
407
what is the result on a neonate of a mother with a primary infection of cytomegalovirus
cytomegalic inclusion disease
408
is babies are infected with cytomegalovirus prenatally, what is the presentation at birth
encephalitis
hepatitis
thrombocytopenia
409
what virus causes retinitis
cytomegalovirus
410
transplant/infusion patients are at risk for developing cytomegalovirus. what are the 2 main symptoms
pneumonia
hepatitis
411
what virus is the main cause of non-genetic hearing loss in children
cytomegalovorus
412
the risk of passing cytomegalovirus to the fetus increases with __
older gestational age at infection
413
when is the risk for fetal damage caused by cytomegalovirus mother-fetus transmission greatest
infection that occurs early in development
414
how is cytomeglovirus infection in mom determined in a baby with cytomegalovirus
CMV specific IgG
415
what is the main way to test for cytomegalovirus
PCR
416
what is the main way to test for cytomegalovirus
PCR saliva swab
417
what is the 2 main antivirals for cytomegalovirus
which is used more
ganciclovir and valganciclovir
valganciclovir is used more
418
how does ganciclovir work
inhibits viral DNA polymerase and causes DNA chain termination
419
how does cytomegalovirus aid in the activation of ganciclovir antiviral drug
it encodes a protein kinase that phosphorylates and activates the drug
420
what are the downsides to using ganciclovir antiviral drug
more toxic than acyclovir
given IV
can cause fever, rashes, and neutropenia
421
how long is valganciclovir given in symptomatic cytomegalovius patients
6 months orally
422
what is seen histologically in those with cytomegalovirus
"owl eye" inclusion bodies
423
human herpesvirus 6 and 7 infect __, allowing for spread throughout the body
lymph tissue
424
how are human herpesvirus 6 and 7 spread
oral secretions
425
HHV 6 and 7 cause latent infection in what cells
T cells
monocytes
426
what are the 2 main symptoms of infection with HHV 6 or 7
exanthema subitum (maculopapular rash)
high fever
427
tzanck smear is used for what virus family
herpesvirus
428
is picornavirus a DNA or RNA virus
RNA
429
is picornavirus enveloped or nonenveloped
nonenveloped
430
what are the 3 enteroviruses of the picornaviruses
poliovirus
coxsackie virus
echovirus
431
what virus is the most common cause of common viral infection
rhinovirus
432
what are the 2 main viruses that cause common viral infection
1. rhinovirus
2. enterovirus
433
what drug can be used against picornavirus, however it is not FDA approved
pleconaril (picovir)
434
how does pleconaril (picovir) work against picornavirus (not FDA inproved)
binds to picornavirus viral protein 4, preventing assembly of the capsid
435
what is the receptor used by poliovirus
CD155
436
what 2 viruses use CAR as their receptor
coxsackie
adenovirus
437
how is picornavirus able to release its genome into the cytoplasm
the capsid fuses with the endosome membrane, viral proteins undergo conformational changes and removes viral protein 1, viral protein 4 forms a pore, genome is injected
438
how are enteroviruses transmitted
(poliovirus, coxsackie, virus
echovirus)
oral and fecal
439
what is the main ways in which enteroviruses (poliovirus, coxsackie, virus, echovirus) lead to epidemics
water contamination
440
where does primary replication of enteroviruses (poliovirus, coxsackie, virus, echovirus) occur
mucosa and lymphoid tissue of tonsils
441
what is a concern about enteroviruses (poliovirus, coxsackie, virus, echovirus) in terms of spread
virus may be shed in stool for a month or more
442
antibody production of Ig__ and Ig__ provide a protection against enteroviruses (poliovirus, coxsackie, virus, echovirus)
IgA
IgG
443
once poliovirus (an enterovirus) is acquired fecal or orally, it replicates in the cervical lymph nodes, created viremia, then is spread to __
spinal cord
444
are most poliovirus infections symptomatic or asymptomatic
asymptomatic
445
why has it been difficult to completely eradicate poliovirus
most people are asymptomatic
since it is an RNA virus, it is highly prone to mutation-->increased serotypes
446
what are the 4 types of infections poliovirus can cause
asymptomatic
abortive poliomyelitis (minor illness)
non-paralytic poliomyelitis (aseptic meningitis)
paralytic poliomyelitis
447
pregnancy increases the risk for which poliovirus infection
paralytic poliomyelitis
448
how does non-paralytic polio (aseptic meningitis) differ from abortive poliomyelitis
non-paralytic causes signs of meningitis such as muscle stiffness and pain
449
what is the symptom progression of paralytic polio
initial fever and headache
1-10 days later- rapid progression of flaccid paralysis, painful muscle aches and spasms
450
what virus causes flaccid paralysis
paralytic polio
451
what is the presentation of flaccid paralysis caused by paralytic polio
often worse on one side
452
what are the 3 types of paralytic polio
spinal
bulbar
bulbospinal
453
how does spinal polio differ from bulbar polio
spinal affects motor neurons of spinal cord (causes paralysis of arms/legs)
bulbar affects motor neurons of the brainstem (affects ability to speak/breath/swallow)
454
iron lungs are occasionally used for what viral infection management
bulbar polio
455
what is post-polio syndrome
deterioration of the residual function of the affected muscles
456
how long after initial polio infection does post-polio syndrome usually occur
30-40 years
457
the first polio virus was what type of vaccine
killed
458
is the live or killed polio currently used
killed (inactive-IPV)
459
what is the main advantage of using the live attenuated polio vaccine
it replicates in the GIT, allowing high nasal and duodenal IgA production
460
what is the main disadvantage of using the live attenuated polio vaccine
reversion to a virulent strain may occur (its an RNA virus so there is high risk for mutations)
461
what is the main reason we use the killed polio vaccine in the US
we have gotten rid of the wildtype virus, so there is no purpose in risking the chance of reversion
462
what vaccines are included in the Pediarix combo vaccine given to children
IPV (inactive poliovirus)
DTaP
HepB
463
coxsackie A viruses target mainly __
coxsackie B viruses target mainly __
A= skin/mucous membranes
B= heart/thorax region
464
what bacteria cause herpangina
coxsackie A
465
what virus causes hand foot mouth disease
coxsackie A
466
how do the oral lesion of herpesvirus differ from herpangina caused by coxsackie A
herpesvirus- slightly raised, wet look
herpangina- more flat look
467
what serotype of coxsackie virus causes hand foot mouth disease
A16
468
what virus causes pleurodynia
coxsackie B
469
what is pleurodynia (Bornholm disease/epidemic myalgia), caused by coxsackie B
intermittent stabbing chest pain
470
what virus causes myocarditis/pericarditis
coxsackie B
471
coxsackie B (serotype 4) has been associated with what autoimmune condition
type 1 diabetes
local infection-->inflammation-->tissue damage-->release of islet autoantigen-->restimulation of resting autoreactive T cells-->islet cell destruction
472
what is the lab technique used to diagnose coxsackie virus
rt-PCR for viral genes in pharynx, feces, or CSF
473
what virus causes acute hemorrhagic conjunctivits
echovirus (serotype 70)
474
what viruses cause aseptic meningitis
poliovirus
*echovirus
475
what are the lab values for viral meningitis from a CSF sample
elevated WBC
slightly elevated protein
normal glucose
*bacterial or fungal meningitis cause low glucose
476
what virus causes neonatal encephalomyocarditis syndrome
coxsackie B or echovirus 11
477
what are the signs of neonatal encephalomyocarditis syndrome
sudden dyspnea, cyanosis, tachycardia
478
what virus causes hemorrhagic hepatitis syndrome
echovirus 11
479
what is the main illness caused by echovirus
meningitis
480
what temperature does rhinovirus prefer to grow at
33C
481
what is the effect of rhinovirus preferring to grow at 33C rather than 37C
cause symptoms focused in the URT
482
what receptor does rhinovirus use
ICAM
483
rhinovirus infections peak at what time of the year
fall and spring
484
hepatitis A is part of what virus family
picornavirus
485
hepatitis A is very resistant. what inactivates it (3)
boiling
formaldehyde
chlorine
486
how is hepatitis A released from the cell
exocytosis (most nonenveloped are released by lysis)
487
hepatitis A and E are spread through __
hepatitis B and C are spread through __
A+E= fecal or oral
C+B= sexual transmission
488
how is hepatitis A able to be spread so easily
virus sheds before or in absence of symptoms in stool
489
since hepatitis A is an enterovirus, it can be spread by what common source
contaminated water
490
the site of replication of hepatitis A is __
liver
491
what is the in incubation period of hepatitis A
3-4 weeks (can be up to 50 days)
492
what is the symptom progression of hepatitis A
symptoms 15-50 days after exposure
symptoms intensify for 4-6 days
jaundice/fever/etc.
493
do symptoms increase or decrease during the icteric (jaundice) phase of hepatitis A
decrease
494
what can be used to treat hepatitis A prophylaxis if given before or shortly after exposure
immune serum globin- IgG from a patient with a past infection or who has been vaccinated
*passive immunity
495
hepatitis A vaccine should be given at what age
12-15 months
496
hepatitis E is spread through what route
oral fecal
497
what is the only way to differentiate hepatitis A from E
serology
498
what virus is the main cause of enterically transmitted hepatitis
hepatitis E
499
are caliciviruses DNA or RNA viruses
RNA
500
what virus is include in the calciviridae viruses
norovirus
501
how is norovirus transmitted
fecal oral (usually in outbreaks)
502
what makes norovirus environmentally stable
it is non-enveloped
503
what does norovirus use as its receptor
human blood group antigen
504
what allows for norovirus to cause diarrhea
damage to villi
505
why is immunity to reinfection of norovirus brief
since it is an RNA virus, it is prone to mutation
short infection time
506
what virus is associated with outbreaks in confined population, and has a very short incubation time before symptoms develop
norovirus
507
what is the leading cause of foodborne gastroenteritis
norovirus
508
what are the 3 main symptoms of norovirus
diarrhea, nausea, vomiting
509
what type of diarrhea is seen with norovirus
watery
510
what is the incubation period of norovirus
24-48 hrs
511
what is the most common way to diagnose norovirus
rt-PCR
512
what can you use to kill norovirus
10% bleach solution
513
are astroviruses RNA or DNA viruses
RNA
514
are astroviruses enveloped or nonenveloped
nonenveloped
515
astrovirus presents symptoms very similar to norovirus. what presentation can be used to differentiate
astrovirus incubation= 48-72 hrs
norovirus= 24-48 hrs
516
where do astrovirus replicate
epithelial cells of small intestine
517
how are astrovirus transmitted
contaminated food/water (fecal oral)
518
are rotaviruses RNA or DNA viruses
RNA
519
are rotaviruses enveloped or nonenveloped
nonenveloped
520
what is significant about the genome of rotaviruses
it's contains segmented dsRNA
521
what is special about the structure of rotavirus
it has a double capsid structure
(triple layer particle- core+2 layers)
522
since rotavirus has a positive sense RNA genome, what enzyme does it bring with it
RNA dependent RNA polymerase
523
what allows for rotavirus to bind to cells
VP4 P antigen
524
what does rotavirus carry with it that allows for such severe diarrhea
enterotoxin NSP4
525
where does rotavirus replicate in the cytoplasm
in viroplasm
(a compartment made by the virus that allows for replication and assembly while decreases the chance of being detected by the host immune system)
526
what is the advantage of rotavirus only doing dsRNA synthesis when capsid protein is available to package the newly made protein
it is not recognized by TLR3 even through it has dsRNA
527
what is the effect of NSP4 enterotoxin released by rotavirus
increased release of Cl-=increased water loss= diarrhea
528
what age group is most susceptible to rotavirus infection
infants
529
rotavirus causes increased diarrhea due to release of __ and stimulation of __
NSP4 enterotoxin
enteric NS-->increased intestinal motility
530
what is the immunity like post-rotavirus infection
short lived IgA protection against VP (viral capsid protein) 4 and 7
531
what is the incubation period for rotavirus
2-4 days
532
diarrhea caused by rotavirus can last for how long
4-5 days
533
what is the presentation of diarrhea caused by rotavirus
watery, green/yellow
534
how can rotavirus be diagnosed
POC test to detect VP6 (viral capsid protein) in stool specimen
535
what is the main way rotavirus can be prevented
vaccination at 2-4 months
(there are currently 2 different rotavirus vaccines available. one is a human live attenuated, the other is a bovine human reassortment live attenuated)
536
is togavirus an RNA or DNA virus
RNA
537
is togavirus enveloped or nonenveloped
enveloped
538
rubella is part of what viral class
togavirus
539
what is the incubation period for rubella
2-3 weeks
540
what are the symptoms of rubella in children
maculopapular rash throughout body
petechia in mouth
541
what are the symptoms of rubella in adults
arthralgia
arthritis
542
what is the main concern about rubella virus that prompted vaccination
congenital rubella can lead to miscarriage or death within the 1st year of life
543
where does rubella replicate
pharynx and spreads to lymph nodes
544
the rash in children and arthralgia/arthritis in adults caused by rubella is believed to be associated with what
type III HSR
545
at what point in children's rubella infection are antibodies generated
when rash appears
546
what type of immunity does rubella provide
lifelong
547
what prevents spread of rubella to the fetus in pregnant woman
serum antibody from vaccination or previous infection
548
if a pregnant women gets rubella, at what stage in pregnancy is congenital rubella the greatest risk to the fetus
1 month before conception-->1st trimester
549
what are the 4 main symptoms of congenital rubella
hearing and vision loss (cataracts)
heart disease
hepatosplenomegaly
petechial and purpural lesions throughout body
550
what 2 viruses lead to a "blueberry muffin" baby with petechial and purpural lesions
cytomegalovirus
rubella
551
if you are dealing with a "blueberry baby" with petechial and purpural lesions caused by cytomegalovirus or rubella, which is the most likely cause
CMV
rubella infections have greatly decreased since the introduction of the MMR vaccine
552
how is rubella spread
respiratory secretions
553
rubella infection is most common in what settings
nurseries
daycares
554
what type of vaccine is the MMR vaccine
live attenuated
555
when is the MMR vaccine given
15 months
556
what type of immunity do you get with rubella
lifeling
557
serology screening for rubella IgG is performed in what groups of patients
women planning to conceive
558
are paramyxoviruses RNA or DNA viruses
RNA
559
are paramyxoviruses enveloped or nonenveloped
Enveloped
560
are paramyxoviruses positive sense or negative sense RNA genome
negative
561
since paramyxoviruses are - sense, what does this mean about what enzyme they must bring
they bring preformed RNA dependent RNA polymerase
562
are shape are paramyxoviruses
helical
563
what viruses contain an F protein allowing for cell-cell fusion, forming a syncytia
paramyxoviruses
564
what 3 proteins of paramyxoviruses allow for attachment to cells
hemagglutinin neuraminidase
hemagglutinin
glycoprotein
565
which paramyxoviruses use hemagglutinin-neuraminidase as their attachment protein
parainfluenza
mumps
566
parainfluenza and mumps viruses use hemagglutinin-neuraminidase as their attachment protein to bind to __
sialic acid
567
what paramyxovirus uses hemagglutinin as their attachment protein
measles
568
measles uses hemagglutinin to attach to what receptor
CD150 and/or CD46
569
what is the incubation peiod for parainfluenza virus
3-6 days
570
what is the main infection caused by parainfluenza
croup
571
parainfluenza virus infects what cells
epithelial cells of the upper respiratory tract
572
what is the immunity like for parainfluenza
short due to multiple serotypes of the virus, but reinfection is milder
573
what sign is visualized on an x-ray in someone with croup caused be parainfluenza virus
steeple
574
parainfluenza virus mainly affects what population
children
575
how is parainfluenza virus transmitted
respiratory droplets
576
what serotype of parainfluenza virus causes croup
1
577
what lab technique can be used to visualize syncytia formation caused by parainfluenza virus (paramyxoviruses)
immunofluorescence
578
what virus causes parotitis
mumps
579
what virus causes orchitis and oophoritis
mumps
580
what 2 viruses can lead to juvenile diabetes
coxsackie B
mumps
581
what is the incubation period for mumps
2 weeks
582
what type of tissue does mumps infect
glandular
583
mumps vaccine is included in MMR. what type of vaccine is MMR
live
584
what viruses can be shed in urine
BK
JC
CMV
Mumps
585
what virus is the most common cause of fatal acute respiratory tract infection in infants and young children
RSV
586
what is the main cause of pneumonia in children under 2
RSV
587
RSV is of main concern in what age group
1-6 months
*especially in premature infants
588
RSV lacks activity of what paramyxovirus proteins
hemagglutinin
neuraminidase
589
what are the main symtposm of RSV
low grade fever
tachypnea
tachycardia
expiratory wheezes
590
what is seen on xray with RSV
bronchiolitis air trapping
591
what is the main secondary infection seen with RSV
otitis media
592
bone marrow transplantation recipients are of main concern with what virus
RSV
593
what are the 3 ways to treat RSV
ribavirin (inhaled, not usually used)
palivizumab (monoclonal antibody against RSV F protein- passive immunity)
aerosolized albuterol
594
RSV and human metapneumovirus both cause the same symptoms. how can they be differentiated
RSV affects children 1-6 months
HMPV affects children 1 year
595
what receptors do measles use
CD46 and/or CD150
596
what is the significance of measles infecting CD150
it's on leukocytes
597
what virus causes photophobia
measles
598
what are the 5 main symptoms of measles
photophobia
high fever
runny nose
Koplik's spots on oral buccal membrane
red, confluent rash
599
what is the symptom progression of measles
flu-like symptoms-->Koplik's spots--> rash
600
what is the effect of measles on memory B cell response
measles depletes memory cells, cause the immune system to have to rebuild memory
601
where does measles replicate
respiratory tract
602
what type of immunity do you get to measles
lifelong
603
what virus can cause giant cell pneumonia
measles
604
who is of greatest concern with developing measles complications
those with a T cell deficiency
605
the rash developed from measles is a response by what cells
T cells
*no rash= decreased T cells= higher chance of further complications and death
606
what virus causes sub-acute sclerosing panencephalitis
measles
607
what is the progression of sub-acute sclerosing panencephalitis
measles before age 2
asymptomatic for 6-15 years
gradual progressive psychoneurological deterioration
608
although it is not common anymore, what caused atypical measles
higher immune response the second time an individual encountered the virus
*received an older vaccine then exposed to the wild type
609
what strain of measles makes up MMR vaccine
edmonston
610
what strain makes up the mumps of MMR vaccine
Jeryl Lynn
611
what strain makes uo the rubella component of MMR vaccine
RA/26-3
612
measles and rubella present similar. how can you differentiate
measles- confluent red rash, koplok spots on buccal membrane
rubella- non confluent pink rash, lymphadenopathy
613
are orthomyxoviruses:
RNA or DNA
segmented or linear
single or double stranded
positive or negative sense
enveloped or nonenvelopes
RNA
segmented
single stranded
negative sense
enveloped
614
orthomyxoviruses are commonly know as __
influenza
615
is influenza A or B spread of more concern
A: humans are not the only host so reassortment and antigenic shift can occur, leading to more strains
616
do influenza have neuraminidase, hemagglutinin, or glycoprotein
neuraminidase
hemagglutinin
617
what part of the influenza virus do we make neutralizing antibodies againt
neuraminidase
hemagglutinin
618
what is the receptor binding, fusion, and penetration protein of influenza
hemagglutinin
619
what are the 2 functions of neuraminidase of influenza virus
cleaves sialic acid of mucous membranes, allowing the virus to cleave oral mucosa to epithelial cells
allows for viral release after budding
620
what part of influenza virus is the target for Zanamivir and Oseltamivir (Tamiflu)
neuraminidase
*prevents viral release
621
what is the function of proteins A, B1, and B2 of influenza
viral RNA dependent RNA polymerase (replication and transcription)
622
what is the function of matrix protein 1 of influenza
viral assembly and budding
623
what is the function of matrix protein 2 of influenza
virus uncoating
624
what is the function of non-structural (NS) 1 protein of influenza
inhibition of host immune response
625
what is the function of non-structural (NS) 2 protein in influenza
export from nucleus
626
what allows for influenza virus entry into the endosome
formation of a hairpin loop allows for fusion then pore formation and release of RNA
627
for influenza virus, viral mRNA is produced in the __
viral mRNA is translated and assembled in the __
produced in nucleus
translated in cytoplasm
628
what virus undergoes cap snatching
influenza (orthomyxovirus)
629
what is involved in cap-snatching performed by influenza
the viral RNA polymerase cuts off the cap from one of the host's own mRNA molecules and uses the cap to start transcription of viral RNA
630
influenza viruses are named according to their __ and __, since they all share the same nucleoprotein and matrix protein
hemagglutinin
neuraminidase
631
antigenic drift occurs in influenza _
antigenic sift occurs in influenza _
drift- A, B, C
shift- A (due to segmented genome and reassortment)
632
what accounts for the symptoms wefeel due to influenza
we get an inflammatory cell response due to monocytes and lymphocytes
633
the main concern with influenza related to pulmonary function is the development of __
pneumonia
634
symptoms of influenza last for __ days and complete within __ days
3 days
10 days
635
what virus causes transverse myelitis
influenza
636
what 2 viruses can cause Guillian Barre syndrome
epstein barr
influenza (orthomyxovirus)
637
what are the 2 main ways to test for influeza
cassette test or rt-PCR
638
what strain is the avian influenza
H5N1
639
how does strain H1N1 influenza differ from H5N1 in terms of the location of the respiratory tract it affects
H1N1- URT
H5N1- LRT
640
since H5N1 binds to cells of the lower respiratory, what condition does it cause
pneumonia
641
what is the significance of H5N1 not binding to the upper respiratory tract
less likely to spread
642
amantadine and rimantidine are both antiviral drugs for influenza (although neither are used due to current development of different strains). how do they work
interfere with viral M2 protein, preventing uncoating
643
how are most influenza viruses cultured
in eggs
644
is coronavirus
RNA or DNA
single or double stranded
positive or negative sense
enveloped or nonenveloped
RNA
single stranded
positive sense
enveloped
645
what are the 2 envelop proteins of coronavirus
E1- transmembrane protein
E2- spik protein
(some also have E3 which is hemagglutinin-neuramidase)
646
what protein does coronavirus use for attachment
E2 (spike)
647
what receptor does coronavirus use
ACE2
648
how does coronavirus transcribe mRNA into a negative strand
viral RNA dependent RNA polymerase
649
what is the incubation period for coronavirus
3-5 days
650
what virus causes low white blood cell count
coronavirus
651
coronavirus does not cause damage to the cell directly, what does
host immune response--> inflammation/leaky blood vessels
652
when is coronavirus viral load at the highest
1-3 days before symptoms
653
what 3 medications can be used for coronavirus
molnupiravir
nirmatrelvir
paxlovid
654
how does molnupirvir, used for coronavirus, work
it's incorporated into replicating RNA and is recognized as either C or U by RNA dependent RNA polymerase
*stops viral replication
655
how does nirmatrelvir, used for coronavirus, work
protease inhibitor prevents virus from reaching final form
656
what virus can perform template switching
coronavirus
657
what allows for coronavirus to template switch
RNA dependent RNA polymerase allows for antigenic drift
658
what virus causes pneumonitis
coronavirus
659
what cells does coronavirus infect
alveolar epithelial cells
660
how does baricitinib used for coronavirus work
JAK-STAT inhibitor
661
how do tocilizumab and sarilumab for coronavirus work
anti-IL6
662
what are the 3 types of coronavirus vaccines
RNA
adenoviral vector
subunit
663
hepatitis __ and __ cause chronic infection
hepatitis __ and __ cause acute infection
hepB and C= chronic
hepA and E= acute
664
are flavivirdae:
DNA or RNA
double or single stranded
positive or negative sense
enveloped or nonenveloped
RNA
single stranded
positive sense
enveloped
665
what virus interacts with the golgi during replication to create a membranous web
hepatitis c
666
how is hepatitis c released
exocytosis- no damage to the cell
667
what is the function of NS5A and NS5B of hepatits c virus
RNA dependent RNA polymerase
668
what is the function of NS 3 of hepatitis c virus
protease activity
669
what 2 drugs are used in hepatitis c infection that target NS5A and NS5B RNA dependent RNA polymerase activity
ledipasvir
sofosbuvir
670
what is the main way in which hepatiis c is transmitted
blood
671
is hepatitis c usually asymptomatic or symptomatic
asymptomatic, chronic infection
672
in hepatitis c infection, what kills the host liver cells
immune response
673
what virus is associated with hepatocellular carcinoma
hepatitis c
674
what is associated with increased chance or hepatocellular carcinoma caused by hepatitis c
alcoholism
675
seroconversion occurs after how long in hepatitis c
7-30 weeks
676
what are the 3 main factors that indicate chronic hepatitis c infection
elevated liver enzymes
anti-HCV antibodies
HCV RNA for at least 6 months
677
what is the main drug for hepatitis c
ledipasvir-sofobuvir (harvoni)
*orally for 8-12 weeks
678
are hepadnaviruses :
DNA or RNA
single or double stranded
enveloped or nonenveloped
DNA
double stranded
enveloped
679
what virs has a partially dsDNA circular genome
hepatitis B
680
what does hepatitis B virus do to distract the host immune system
produces dane particles (empty envelope with no nucleic acid, only hepB surface antigen) draws the immune system to the surface antigen, away from the full virus
681
what components of hepatitis B do we make antibodies against
HBs (surface antigen)
HBc (core antigen)
HBe (pre-core protein)
682
in hepatitis B, what does the P open reading frame code for
what is the function
RNA dependent DNA polymerase
reverse transcriptase
683
what is the function of RNAase H activity in hepatitis B
degrades pre-genomic RNA during synthesis of the negative DNA strand
684
what enveloped virus can remain infective outside of the body for up to 7 days
hepatitis B
685
hepatocytes are injured during hepatitis b infection due to what
MHC class I CD8+ T cell response
686
acute hepatitis B is more common in __, while chronic hepatitis B is more common in __
acute- adults
chronic- infants
687
what lab method is used to determine hepatitis B titers
PCR
688
what is the incubation period for acute hepatitis B before jaundice occurs
2-5 months
689
what antibodies are the first to appear in hepatitis B infection
anti-HBc (against core protein)
690
antibodies againts what component of hepatitis B indicates clearance of the virus
anti-HBs (surface protein)
691
chronic infection of hepatitis B is indicated if what antigen persists in the blood for more than 6 months
HBs (surface antigen)
692
what are the 5 antivirals to treat hepatitis B
lamivudine
adefovir
entecavir
telbivudine
tenofovir
693
what makes up the hepatitis B vaccine
HBs (surface antigen)
694
what type of vaccine is the hepB
subunit
695
what virus must be present for hepatitis D to be present, why
HepB
Hep D uses HBsAg as part of its envelope
696
zoonotic viruses are all DNA or RNA, enveloped or nonenveloped
RNA enveloped
697
are rhabdoviruses:
DNA or RNA
enveloped are non enveloped
single or double stranded
+ or negative sense
RNA
enveloped
single stranded
negative sense
698
what is the infection caused by rhabdovirus
rabies
699
what receptor can rabies virus use
nicotinic acetylcholine receptor
neuronal cell adhesion molecules
p75 neurotrophin receptor
700
what are 2 ways in which rabies and transmitted
infected animal bite
cornal transplant
701
corneal transplant can cause what infection
rabies
702
why does rabies have such a long incubation period
it replicates in cells with a slow turnover
703
where does rabies virus replicate
neurons (dorsal root ganglion)
muscle cells
704
what virus causes aerophobia and hydrophobia
rabies
705
what is seen histologically for someone who dies of rabies
negri bodies
706
what ais given as post-exposure prophylaxis for rabies
killed vaccine+human rabies Ig
707
are filoviruses :
RNA or DNA
enveloped or non-enveloped
single or double stranded
positive or negative sense
RNA
enveloped
single
negative
708
what are the 2 infections filovirus includes
Marburg
Ebola
709
how are ebola and marbug virus spread
secretions
710
what 3 viruses causes hemorrhagic fever
ebola
marburg
hantavirus
711
what type of vaccine is the ebola vaccine
subunit
712
are bunyaviruses:
DNA or RNA
single or double stranded
enveloped or nonenveloped
positive or negative sense
RNA
single stranded
enveloped
negative sense
713
what are the 4 segmented viruses
Bunyavirus
Orthomyxovirus
Arenavirus
Reovirus
714
what is the main bunyavirus
hantavirus
715
hantavirus causes hemorrhagic fever with what other symptom
renal syndrome
716
what is the main infection caused by hantavirus
hantavirus pulmonary syndrome
717
what is the main symptom of hantavirus pulmonary syndrome
massive fluid infiltration of both lungs
718
in what region is hantavirus found
southwestern US
719
are arenavirus:
DNA or RNA
single or double stranded
enveloped or nonenveloped
positive or negative sense
RNA
single stranded
enveloped
negative sense
720
which virus contains host cell ribosomes
arenavirus
721
what 2 viruses have ambisense genome
(can be read as a positive or negative sense RNA)
bunyavirus
arenavirus
722
what virus causes lymphocytic choriomeningitis virus
arenavirus
723
how is lymphocytic choriomeningitis spread
mice and hamster urine/saliva/feces
724
what virus can lead to intrauterine infection leading to fetal death, hydrocephalus, and/or chorioretinitis
lymphocytic choriomeningits virus (caused by arenavirus family)
725
what are the 4 requirements for a virus to be considered an arbovirus
1. infects vertebrae and invertebrae
2. initiate viremia in a vertebrate host to allow acquisition of the virus by the invertebae vector
3. initiate a persistent productive infection of the salivary glands of the invertebrae to provide virus for the infection of other host animals
4. not be pathogenic in the arthropod that the bug stops biting
726
what is the incubation period for arbovirus primary viremic spread causing fever and myalgia
less than 1 week
727
what is the incubation period for arbovirus causing encephalitis
1-2 weeks
728
what is the incubation period for arbovirus causing viral hemorrhagic fevers
up to 3 weeks
729
what treatment should be avoided in those with viral hemorrhagic fevers
IM/IV insertion
anticoagulants
730
are bunyaviruses:
DNA or RNA
single or double stranded
enveloped or nonenveloped
positive or negative sense
RNA
single stranded
enveloped
negative sense
731
are flaviviruses:
DNA or RNA
enveloped or nonenveloped
single or double stranded
positive or negative sense
RNA
enveloped
single stranded
positive sense
732
where do flaviviruses replicate
in antigen presenting cells (dendritic cells and macrophages)
733
what causes dengue fever shock syndrome
an initial infection lead to IgG against that serotype but after getting infected with another serotype, IgG tagged the virus but didn't neutralize it
the virus was then opsonized and brought into the APC, leading to increased inflammation
734
what type of vaccine is used for dengue fever
live attenuated
735
who should receive the dengue fever vaccine
only those who have been infected before
736
what is the main symptom of yellow fever
jaundice
737
who is at the greatest risk for St. Louis encephalitis
elderly
738
when is west nile virus most present (what time of year)
late summer/early fall
739
what is the main concern with zika virus
in utero infection--?microencephaly
740
besides from the bite of an Aedes mosquito, how else is zika virus transmitted
sexual contact
741
are reoviruses:
DNA or RNA
double or single stranded
enveloped or nonenveloped
positive or negative sense
RNA
double
nonenveloped
742
what virus causes Colorado tick fever
colivirus (reovirus family)
743
what tick transmits colorado tick fever
dermacentor
744
symptoms of Colorado tick fever are similar to Rocky Mountain spotted fever. how do they differ
Rocky Mountain causes a rash
Colorado tick does not
745
are retroviruses:
DNA or RNA
enveloped or nonenveloped
positive or negative sense
RNA
enveloped
2 copies of positive sense RNA
746
what enzyme is needed for retroviruses
RNA dependent DNA polymerase
747
what proteins do retrovirus gag genes code for
structural
748
what proteins do retrovirus pol genes code for
polymerase
749
what proteins do retrovirus env genes code for
viral envelope
750
what is the function of retrovirus LTR (long terminal repeat) gene
transcription initiation
751
what primer do retroviruses use
its own tRNA
752
what virus causes human T cell leukemia virus
retrovirus oncovirus
753
what virus causes human immunodeficiency virus (HIV)
retrovirus lentivirus
754
what cells does human T cell leukemia virus infect
CD4+ T cells
755
what cells does human T cell leukemia virus infect
CD4+ T cells
756
how is human T cell leukemia virus spread
breast feeding, blood, sexual contact
757
is what region is human T cell leukemia virus most common
southern Japan
758
what is the progression of cancer development caused by human T cell leukemia virus, leading to adult T cell lymphoma/leukemia
usually infected through breast feeding then have another mutation as an adult --> cancer (40 years post infection)
759
what is seen histologically in human T celll lymphoma/leukemia virus
atypical T lymphocytes (flower cells)
760
what are the symptoms of human T cell leukemia virus associated paraparesis
demyelination of nerves of spinal cord--> MS symptoms
761
what may be the cause of human T cell leukemia virus associated paraparesis (HAM/TSP) leading to demyelination of the nerves of the spinal cord
autoimmune reaction producing antibodies against viral Tax protein
